Microsoft plans to introduce a new Teams call handler starting in January 2026 to reduce launch times and improve call performance in the Windows desktop client.
New Call Handling Process
After the rollout, a new process named ms-teams_modulehost.exe will manage calling features, running as a child process under the main ms-teams.exe application. According to Microsoft, this change is designed to improve performance and startup time for calling features in the Microsoft Teams Desktop Client for Windows.
The new child process will handle the calling stack separately from the main application, which is expected to optimize resource usage and provide smoother meeting experiences.
Impact on Users
This architectural change will not alter existing user workflows or require additional training. From the user’s perspective, calling features will work as they do now, with the improvements occurring entirely in the background.
Guidance for IT Administrators
IT administrators should prepare for the update by allowlisting the new ms-teams_modulehost.exe process in security tools and endpoint protection platforms. This will help prevent false-positive detections and avoid disruptions to calling functionality.
Organizations are also advised to inform helpdesk and support staff about the new process. This will reduce confusion during troubleshooting and help address any concerns about unfamiliar executables appearing on users’ systems.
Rollout Schedule
The rollout is scheduled to begin in early January 2026 across all deployment environments, including worldwide, GCC, GCC High, and DoD tenants. Microsoft expects the deployment to be completed by late January 2026.
Recent Security and Performance Enhancements
Earlier this year, Microsoft began strengthening Microsoft Teams against malicious URLs and dangerous file types shared in chats and channels. Teams now also warns users when they send or receive private messages containing links that have been flagged as malicious.
In addition, Microsoft is rolling out a feature that automatically blocks screen-capture attempts during Teams meetings, helping protect sensitive information. Users will also be able to report messages that have been incorrectly flagged as security threats.
Beyond Teams, Microsoft has started testing File Explorer preloading in Windows 11, aiming to further improve system performance and reduce application launch times.
