This seems to be something to do with the OS.
1. You may firstly want to perform a system restore using only the keyboard tab and enter key, from safe mode, to a date when the unit was working fine.
2. If issue persists, reinstall the OS and check (Eliminates any software related issue)
3. Lastly, run a hard drive test in bios > Hard drive may be faulty and may need replacement
Myself, been there done it..