Hey... while ago I had a problem with my computer so I installed windows again, then my computer used to work normal like a new computer.. but then again I had this problem that none of the mouse, drivers and etc worked so I installed windows again now everything works excpet I can't open any files.
What should I do?

Appreciate your help

Could be due to one of the following reason.

1. Either your hard drive is corrupted, which can only be fixed through reformatting or by getting a new hard drive, or
2. Your computer is infected by a virus.

In both cases I suggest that you take your computer to a computer shop and have it be examined by a computer specialist.