Viruses & Malware can cause such behavior. Corrupted OS files can also cause this action. The first step should be to run Malwarebytes (Free Version)
and Windows Defender Offline to make sure your system hasn't been compromised by something. Windows Defender Offline
It would be advisable to make WDO on a different, clean PC being that the scanner could be compromised if you make it on yours, given it's behavior.
Let us know the results of the scans. And as CommandoBob stated, the kind of error messages showing up in the event log will be helpful also.