Converted MBR SSD to GPT, everything but Steam Games work fine

[DatMiddy]

Windows 10 user, wanted to get Windows 11 compliant. Converted a EVO 870 using MBR2GPT tool in windows, went fine. Rebooted, changed Asus B550-E Gaming motherboard BIOS to disabled CSM, Enable ftpm and Secure boot. OS Type is is Windows UEFI mode. Everything works as it should.

Until I try to start a Steam game. Steam is installed on a MBR drive, with library spread across 3 ssds. Yesterday I tried playing numerous games, and they all start to launch, and then my computer hard resets.

When I launched Spiderman, I got a warning about the pagefile not being large enough, went and figured out somehow the page file had been turned off. Fixed that back to letting Windows Manage it, but with 32gb of ram it's weird to even need it.

Going to go and install Epic Games to see if games there also immediately hard crash me. Not seeing anything in the Event Viewer that is abnormal, but pulling my hair out trying to figure this out. I don't want to have to reinstall windows, setting all the custom mods I have for my games back up would be a nightmare.

[Zef]

For basic health checks just to be sure you can always run a:

SFC /SCANNOW

DISM /Online /Cleanup-Image /RestoreHealth

CHKDSK /F /R /X


Why don't you just move your Steam install (and games) to another disk? After that just format the MBR drive to GPT and move everything back?