To disable the Roblox desktop app on Windows 11/10, you need to use parental control or application control software. Program Blocker by TheWindowsClub is a great free app to block the Roblox app.

Roblox provides a desktop app version that can be installed using its installer file. Also, its UWP or Universal Windows Platform version is available that you can install from the Microsoft Store.

To restart the PC, go to Windows > Power > Restart. Try a different version of the Roblox app. You can access the game through its dedicated launcher or the Microsoft Store app.