OK. Then what you really need to try is doing a System Restore (not to be mistaken for other operations that do not have precisely that name, and that might erase the data on your disk! so don't follow these instructions inaccurately.)
Here's how... though if you have Windows 10 or Windows 8.1, this may not apply, if so let me know before proceeding:
System Restore can be done by the following:
Start - [All] Programs - Accessories - System Tools - System Restore
and choose to Restore system to a previous [etc.], then from the calendar-like interface, choose the first restore point *before* the problem started, then do the restoring.
(Warning: it may help to first disconnect from the internet, then also disable - temporarily, i.e. turn Off - your anti-virus utility, since they can often interfere with the Restore operation completing successfully.... before doing a System Restore.)
The computer will grind away for a while, then restart automatically, then grind away some more, and hopefully will come up with a message that the Restore operation was fully successful.
And hopefully that will cure the problem.
(PS: Do not choose to do a System Restore if you have recently installed any Microsoft software of any considerable cost. Its installation may be reversed, and you may lose money that way. Let me know if you think that's the case, and I will advise you further as to what to do.)