MoUSOCoreWorker is a normal part of Windows. It's a component of Microsoft's Unified Update Platform Microsoft. Don't end the MoUSOCoreWorker process in Task Manager unless it seems to be stuck consuming large quantities of system resources, as it's necessary for system updates.
A mysterious executable that is causing high disk usage, high RAM consumption, and using your CPU can be alarming. But don't worry --- mousocoreworker.exe is a normal part of Windows 10 and Windows 11. Here's what you need to know.
Windows updates are notorious for being less than perfect. Microsoft attempted to improve the update experience a few years after Windows 10 was released with the Unified Update Platform (UUP). The UUP was included with Windows 11 from the beginning.
The Unified Update Platform can be broken into multiple layers, each of which handles a different part of the update process. The mousocoreworker.exe process is part of the new update platform.
The "USO" in MoUSOCoreWorker stands for "Update Session Orchestrator" --- the component of the update process that coordinates the order in which updates are downloaded and installed.
Microsoft provided the table below on its website to explain how the new(ish) Unified Update Platform works, though the company didn't include any specific documentation about exactly what mousocoreworker.exe does.
When it is functioning correctly, mousocoreworker.exe should appear in Task Manager when Windows checks for updates, and then disappear afterward.
If mousocoreworker.exe is not working correctly people have noticed that it remains active and using system resources. High disk usage and high RAM usage are particularly common complaints. Usually, the problems occur if there isn't an update running, though it sometimes happens if an update gets stuck. You can open up Task Manager and end the process in either case.
It has also been known to repeatedly wake PCs from sleep and attempt to install an update. If that happens, your best bet is to let it run and try to sort itself out.
If letting it run or restarting the process doesn't resolve the problem, you probably need to take additional steps to fix Windows Update.
A glitch is the most likely explanation if your mousocoreworker.exe isn't behaving properly, but it is always possible that malware is masquerading as a legitimate Windows process. Malware has been disguised as legitimate software and services many times in the past.
If you're concerned about the possibility of having a virus, you can always scan your computer with Microsoft Defender or Malwarebytes. They're both excellent and will likely catch any malware running on your system.