There are many reasons why a PC " behaves" this way.
These annoying " gliches" may be caused by
running 2 AV 's,
Browser add ons or you may have unnecessary programs running in the background etc....
*List all the Security software you have ever had installed & currently have now on your computer please.
*Please download the free version of Malwarebytes.
Update it immediately.
Do a full system scan
Let us know the results at the end.
* Browser add ons can create problems.
Check how many you have on your various browsers.
Is each & every one really needed?
* Try in safe mode; report back if it works properly. Safe Mode
* Have you checked in Event Viewer?
Type eventvwr in search.
Go to the Windows Logs > Application / System > in the left hand column.
Note anything in red that relates to the problem.
Please record the event ID, and the Source Code and tell us what they are.