check before: 2026-01-01
Product:
Teams, Windows
Platform:
Online, US Instances, Windows Desktop, World tenant
Status:
Change type:
Admin impact, Feature update, Updated message, User impact
Links:
Details:
Summary:
The planned renaming of the Teams Calling and Meetings executable was canceled due to a Windows fix in versions 24H2 and 25H2. No admin action is needed. A new process, ms-teams_modulehost.exe, will be introduced for calling features to improve performance, requiring endpoint allowlisting and QoS updates.
Details:
Updated January 15, 2026: We are canceling a proposed change related to renaming the existing Calling and Meetings executable.
No action is required from administrators. This change did not introduce a new binary. It involved renaming the existing executable used for Calling and Meetings as a workaround for a Windows compatibility issue.
What Happened?
To reduce administrative effort, we partnered with the Windows team to deliver the fix for a Windows compatibility issue. With the Windows fix now fully rolled out in Windows 24H2 and 25H2, the executable name change is no longer required and has been rolled back.
Was this a security, reliability, or compliance issue?
This was not a security or compliance issue.
It was a platform compatibility issue in Windows.
No customer data, identity, or tenant configuration was at risk.
Was my tenant impacted?
Only organizations participating in our Technology Adoption Program (TAP) were affected. Specifically, the change applied only to the TAP Admin earlyadopter subset (Ring 1.5).
If your organization does not participate in the Microsoft Technology Adoption Program, you were not impacted in any way. The change has been fully rolled back for TAP participants, with no lasting configuration or behavioral changes on client machines. No administrator action is required.
What if we haven't deployed recent Windows updates yet?
We understand that many enterprises deploy Windows cumulative updates on managed timelines.
There is no risk or degradation if the referenced Windows KBs are not installed.
New features that depend on these Windows updates will explicitly check for the presence of the required KBs and will only enable when they are available.
If the KBs are not installed, those features simply remain disabled-no functionality breaks and no admin action is required.
Windows updates that include the fix
The Windows compatibility fix is included in Windows updates for versions 24H2 and 25H2, delivered through KB5068861.
What to expect next?
No changes to admin configuration or tenant settings
No service disruption
---Original message---
[Introduction]
We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences.
[When this will happen:]
Rollout will begin early January 2026 and complete by late January 2026.
Note: Timelines may shift due to year-end feature flag rollout freeze.
Change Category:
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Scope:
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Release Phase:
Created:
2025-11-25
updated:
2026-01-16
Task Type
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Docu to Check
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MS How does it affect me
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MS Preperations
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MS Urgency
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MS workload name
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summary for non-techies**
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Direct effects for Operations**
Performance Degradation
If the new process ms-teams_modulehost.exe is not allowlisted, users may experience degraded performance in calling features, leading to delays and interruptions during calls.
- roles: End Users, Helpdesk Staff
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams
Increased Support Tickets
Without proper communication about the new process, helpdesk staff may receive an influx of support tickets related to confusion over the new process and its impact on Teams functionality.
- roles: Helpdesk Staff, IT Support
- references: https://support.microsoft.com/en-us/topic/november-11-2025-kb5068861-os-builds-26200-7171-and-26100-7171-2e0512e4-3ad4-4da6-958c-a468a1af949e
User Experience Disruption
If QoS settings are not updated for the new process, users may face disruptions in call quality, leading to a poor user experience during meetings and calls.
- roles: End Users, Network Administrators
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams
Documentation Inaccuracy
Failure to update internal documentation regarding the Teams process names may lead to confusion and misinformation among staff, affecting troubleshooting efforts.
- roles: IT Documentation Managers, Helpdesk Staff
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams
Security Risks
If security software does not allowlist the new process, it may be blocked, leading to potential security risks or functionality issues in Teams calling features.
- roles: Security Administrators, End Users
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams
Configutation Options**
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Opportunities**
Improved Resource Management
The introduction of the ms-teams_modulehost.exe process allows for better resource allocation by separating calling features from the main Teams application. This can lead to reduced CPU and memory usage, improving overall system performance during calls and meetings.
- next-steps: Monitor performance metrics post-implementation to quantify improvements in resource usage. Consider further optimization based on user feedback.
- roles: IT Administrators, Helpdesk Staff, End Users
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams, https://support.microsoft.com/en-us/topic/november-11-2025-kb5068861-os-builds-26200-7171-and-26100-7171-2e0512e4-3ad4-4da6-958c-a468a1af949e
Enhanced User Experience
With the new process dedicated to handling calls, users may experience improved call quality and reduced latency during meetings, leading to a more seamless communication experience. This could increase user satisfaction and productivity.
- next-steps: Gather user feedback through surveys or direct communication to assess the perceived improvements in call quality. Use this data to inform future IT strategies.
- roles: End Users, Team Leaders, IT Administrators
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams, https://support.microsoft.com/en-us/topic/november-11-2025-kb5068861-os-builds-26200-7171-and-26100-7171-2e0512e4-3ad4-4da6-958c-a468a1af949e
Streamlined IT Operations
The requirement to allowlist the new process and update QoS settings can streamline IT operations by standardizing procedures for application management. This can also lead to reduced troubleshooting time as helpdesk staff will have clear guidelines on the new process.
- next-steps: Update internal documentation and training materials for helpdesk staff regarding the new process and QoS settings. Conduct training sessions to ensure staff are prepared for user inquiries.
- roles: IT Administrators, Helpdesk Staff, Compliance Officers
- references: https://learn.microsoft.com/microsoftteams/qos-in-teams, https://support.microsoft.com/en-us/topic/november-11-2025-kb5068861-os-builds-26200-7171-and-26100-7171-2e0512e4-3ad4-4da6-958c-a468a1af949e
Potentional Risks**
XXXXXXX ... paid membership only
IT Security**
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explanation for non-techies**
Imagine your computer as a busy office building, with each program being a different department. Microsoft Teams is like the communications department, handling all your calls and meetings. Recently, there was a plan to rename one of the office rooms (an executable file) to fix a compatibility issue with the building's infrastructure (Windows). However, the building management (Windows team) fixed the infrastructure issue, so the room renaming was no longer necessary. This means there’s no need for any administrative action or concern about security or compliance. It was simply a matter of making sure everything worked smoothly together.
Now, there's a new development. To make the communications department (Teams) work more efficiently, a new assistant (process) named ms-teams_modulehost.exe is being introduced. Think of this assistant as someone who specifically handles phone calls, freeing up the main department (ms-teams.exe) to focus on other tasks. This should make everything run faster and more smoothly, like reducing wait times for calls.
For those managing the office building (IT admins), it's important to ensure that security and management systems recognize this new assistant and allow it to work without interference. This means updating security settings to recognize ms-teams_modulehost.exe as part of the team. It's like adding the new assistant to the office directory so security knows they belong there.
There's no change in how the department (Teams) looks or operates from the outside, so employees won't notice anything different in their day-to-day work. However, it's a good idea to inform the helpdesk staff about this new assistant, so they aren't surprised if they see it listed in the office directory (Task Manager) during troubleshooting.
Overall, this change is about improving efficiency without disrupting the current workflow, ensuring that everything runs smoothly and efficiently in the background.
** AI generated content. This information must be reviewed before use.
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change history
| Date | Property | old | new |
| 2026-01-16 | MC Messages | Updated December 17, 2025: We understand that implementing the current guidance involves considerable effort for administrators, and we are actively working to reduce this impact. We are exploring ways to make policy changes as seamless as possible, in close partnership with the Windows team.
Given this ongoing work, we recommend pausing any testing or configuration updates related to this feature. Updated instructions and revised guidance will be shared as part of the formal communication planned for January 2026. Thank you for the valuable feedback we've received. We are currently reassessing the rollout timelines to ensure alignment with your needs and operational requirements. You can expect a formal update from us by mid to late January 2026. [Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Updated rollout timing will be announced in January 2026 Note: Timelines may shift due to year-end feature flag rollout freeze. | Updated January 15, 2026: We are canceling a proposed change related to renaming the existing Calling and Meetings executable.
No action is required from administrators. This change did not introduce a new binary. It involved renaming the existing executable used for Calling and Meetings as a workaround for a Windows compatibility issue. What Happened? To reduce administrative effort, we partnered with the Windows team to deliver the fix for a Windows compatibility issue. With the Windows fix now fully rolled out in Windows 24H2 and 25H2, the executable name change is no longer required and has been rolled back. Was this a security, reliability, or compliance issue? This was not a security or compliance issue. It was a platform compatibility issue in Windows. No customer data, identity, or tenant configuration was at risk. Was my tenant impacted? Only organizations participating in our Technology Adoption Program (TAP) were affected. Specifically, the change applied only to the TAP Admin earlyadopter subset (Ring 1.5). If your organization does not participate in the Microsoft Technology Adoption Program, you were not impacted in any way. The change has been fully rolled back for TAP participants, with no lasting configuration or behavioral changes on client machines. No administrator action is required. What if we haven't deployed recent Windows updates yet? We understand that many enterprises deploy Windows cumulative updates on managed timelines. There is no risk or degradation if the referenced Windows KBs are not installed. New features that depend on these Windows updates will explicitly check for the presence of the required KBs and will only enable when they are available. If the KBs are not installed, those features simply remain disabled-no functionality breaks and no admin action is required. Windows updates that include the fix The Windows compatibility fix is included in Windows updates for versions 24H2 and 25H2, delivered through KB5068861. What to expect next? No changes to admin configuration or tenant settings No service disruption ---Original message--- [Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. |
| 2026-01-16 | MC Last Updated | 12/17/2025 19:18:50 | 2026-01-15T17:17:06Z |
| 2026-01-16 | MC prepare | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Make sure the same QoS settings applied to ms-teams.exe are also applied to ms-teams_modulehost.exe. Refer to this page for details: Implement Quality of Service (QoS) in Microsoft Teams DO NOT remove QoS settings of ms-teams.exe. Only add QoS settings for ms-teams_modulehost.exe. [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. https://learn.microsoft.com/microsoftteams/qos-in-teams | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Make sure the same QoS settings applied to ms-teams.exe are also applied to ms-teams_modulehost.exe. Refer to this page for details: Implement Quality of Service (QoS) in Microsoft Teams DO NOT remove QoS settings of ms-teams.exe. Only add QoS settings for ms-teams_modulehost.exe. [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. https://learn.microsoft.com/microsoftteams/qos-in-teams https://support.microsoft.com/en-us/topic/november-11-2025-kb5068861-os-builds-26200-7171-and-26100-7171-2e0512e4-3ad4-4da6-958c-a468a1af949e |
| 2026-01-16 | MC Summary | Thank you for the valuable feedback we’ve received. We are currently reassessing the rollout timelines to ensure alignment with your needs and operational requirements. You can expect a formal update from us by mid to late January 2026. | The planned renaming of the Teams Calling and Meetings executable was canceled due to a Windows fix in versions 24H2 and 25H2. No admin action is needed. A new process, ms-teams_modulehost.exe, will be introduced for calling features to improve performance, requiring endpoint allowlisting and QoS updates. |
| 2025-12-18 | MC Messages | Updated November 26, 2025: We have updated the content below to provide additional information. Thank you for your feedback.
[Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Worldwide, GCC, GCC High, and DoD: Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. | Updated December 17, 2025: We understand that implementing the current guidance involves considerable effort for administrators, and we are actively working to reduce this impact. We are exploring ways to make policy changes as seamless as possible, in close partnership with the Windows team.
Given this ongoing work, we recommend pausing any testing or configuration updates related to this feature. Updated instructions and revised guidance will be shared as part of the formal communication planned for January 2026. Thank you for the valuable feedback we've received. We are currently reassessing the rollout timelines to ensure alignment with your needs and operational requirements. You can expect a formal update from us by mid to late January 2026. [Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Updated rollout timing will be announced in January 2026 Note: Timelines may shift due to year-end feature flag rollout freeze. |
| 2025-12-18 | MC IsMajorChange | True | False |
| 2025-12-18 | MC Last Updated | 11/26/2025 19:18:12 | 2025-12-17T19:18:50Z |
| 2025-12-18 | MC End Time | 02/23/2026 09:00:00 | 2026-02-02T09:00:00Z |
| 2025-12-18 | MC Summary | Microsoft Teams Desktop Client for Windows will introduce a new process, ms-teams_modulehost.exe, to handle calling features separately, improving performance and startup time. Rollout begins January 2026. Admins should allowlist the new process in security software and inform helpdesk staff; no user workflow changes expected. | Thank you for the valuable feedback we’ve received. We are currently reassessing the rollout timelines to ensure alignment with your needs and operational requirements. You can expect a formal update from us by mid to late January 2026. |
| 2025-11-27 | MC Messages | Updated November 25, 2025: We have updated the content below to provide additional information. Thank you for your feedback.
[Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Worldwide, GCC, GCC High, and DoD: Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. | Updated November 26, 2025: We have updated the content below to provide additional information. Thank you for your feedback.
[Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Worldwide, GCC, GCC High, and DoD: Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. |
| 2025-11-27 | MC Last Updated | 11/25/2025 19:41:09 | 2025-11-26T19:18:12Z |
| 2025-11-27 | MC prepare | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Make sure the same QoS settings applied to ms-teams.exe are also applied to ms-teams_modulehost.exe. Refer to this page for details: Implement Quality of Service (QoS) in Microsoft Teams [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. https://learn.microsoft.com/microsoftteams/qos-in-teams | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Make sure the same QoS settings applied to ms-teams.exe are also applied to ms-teams_modulehost.exe. Refer to this page for details: Implement Quality of Service (QoS) in Microsoft Teams DO NOT remove QoS settings of ms-teams.exe. Only add QoS settings for ms-teams_modulehost.exe. [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. https://learn.microsoft.com/microsoftteams/qos-in-teams |
| 2025-11-26 | MC prepare | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Learn more about Teams performance improvements: https://learn.microsoft.com/microsoftteams/Microsoft Teams documentation. [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. | Update endpoint management and security software to allowlist ms-teams_modulehost.exe alongside ms-teams.exe.
Communicate this change to helpdesk staff to avoid confusion during troubleshooting. Update internal documentation if you reference Teams process names. Make sure the same QoS settings applied to ms-teams.exe are also applied to ms-teams_modulehost.exe. Refer to this page for details: Implement Quality of Service (QoS) in Microsoft Teams [Compliance considerations:] No compliance considerations identified, review as appropriate for your organization. https://learn.microsoft.com/microsoftteams/qos-in-teams |
| 2025-11-26 | MC IsMajorChange | False | True |
| 2025-11-26 | MC Last Updated | 11/25/2025 01:01:09 | 2025-11-25T19:41:09Z |
| 2025-11-26 | MC Messages | [Introduction]
We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Worldwide, GCC, GCC High, and DoD: Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. | Updated November 25, 2025: We have updated the content below to provide additional information. Thank you for your feedback.
[Introduction] We're improving the performance and startup time of calling features in the Microsoft Teams Desktop Client for Windows. To achieve this, we're introducing a new child process named ms-teams_modulehost.exe that will handle the calling stack separately from the main application process (ms-teams.exe). This change optimizes resource usage and enhances meeting experiences. [When this will happen:] Worldwide, GCC, GCC High, and DoD: Rollout will begin early January 2026 and complete by late January 2026. Note: Timelines may shift due to year-end feature flag rollout freeze. |
| 2025-11-26 | MC Title | Upcoming Change to Teams Desktop Client on Windows | (Updated) Upcoming Change to Teams Desktop Client on Windows |
| 2025-11-26 | MC MessageTagNames | Feature update, User impact, Admin impact | Updated message, Feature update, User impact, Admin impact |
Last updated 1 day ago ago
