Troubleshoot: FAT FILE SYSTEM (fastfat.sys) error in Windows 10
Blue Screen of Death (BSOD) error with FAT FILE SYSTEM (fastfat.sys) restarts the operating system to prevent further damage to the system. FAT FILE SYSTEM ERROR error in Windows 10 is caused by outdated Windows operating system, outdated device drivers, corrupted system files, corrupted hard drives, conflicting folder protection/encryption applications, incorrectly triggered antivirus, and corrupted Windows operating system.
To fix this error, perform the following solution.
What Causes Error FAT FILE SYSTEM (fastfat.sys) in Windows 10
FAT file system error usually occurs after installing new hardware, updating software or system, installing a certain application, loading a system driver, etc. There are several factors that can cause Windows 10 FAT file system errors.