I would try booting from a flash drive with Windows on it and possibly run a disk check. Sounds like your boot disk may be either corrupted or the Windows installation got corrupted data and that requires a complete wipe of the drive through a disk partitioning app and a clean install of Windows. Hope this helps!

Does the fan shut off once you shut the machine down? You may want to check it for dust build up. My brother in law’s PS4 was running hot and the fan was extremely loud until he removed the case, cleaned out the dust and sprayed compressed air throughout the console and it works fine now.