Hi,
have you tried the usual like checking for malware etc? Also when did your problems start? If it was after installing something like an update then removing it might help?
Same with hardware if you fitted something new then see if removing it helps any..
You could try system restore or by pressing F8 when booting, enter the advanced boot menu and click 'last good known configuration'.
If the above fails you might need to start checking hardware:
See if you can run a checkdisk by right-clicking on Computer choosing properties, Tools and then Check now, Make sure you tick all the boxes. If the checkdisk fails to run then you might be looking at a new HDD.
You can check your memory by using this app:
Memtest86.com - Memory Diagnostic
Test one stick at a time so you know which ones are faulty (if any) and do make sure you have your timings correct.