Last week Microsoft announced a small but very significant upgrade for Teams. That is because the company is preparing a performance upgrade for the Teams Desktop Client on Windows by debuting a new dedicated child process.
We say the change is significant as it targets what Microsoft says is one of the most resource-intensive aspects of Teams, and that is call handling. Thus by offloading this workload into a dedicated process, Microsoft aims to improve startup times and optimize system resource usage, and this should technically enhance the meeting experiences for end users.
This also appears to be a better alternative than simply preloading apps like the company now does with "Office Startup Boost".
If you are wondering how it is being done, Microsoft says that beginning in early January 2026, a separate Windows process named ms-teams_modulehost.exe will run alongside the main Teams executable file (ms-teams.exe), thus separating the calling stack from the core Teams application.
It writes: "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."
For IT admins and system administrators, Microsoft notes that the new process will appear in Task Manager under the main Teams entry. While the addition is designed to be seamless, endpoint management and security software must be updated to allowlist ms-teams_modulehost.exe alongside ms-teams.exe; failure to do so could result in unnecessary alerts or blocked functionality as after all, false alerts are fairly common.
The company has also recommended that admins should NOT remove QoS (Quality of Service) settings for ms-teams.exe and that they should only add new QoS settings for ms-teams_modulehost.exe.
Besides a performance boost though, Microsoft has added that no changes to user workflows or user interface (UI) should be expected. Those who have access to Microsoft 365 Admin Center portal can view it under ID MC1189656.