explorer.exe crashes and restarts when certain actions are performed

Hello,

So for the past month or so, explorer.exe has been crashing continuously. It happens on several occasions...

-Most notable when I first boot up Windows 7, it crashes and restarts in an assiduous manner, for maybe 10-15 times until it stops suddenly and starts working again

-When accessing files which force explorer to open, e.g. when I open a document, open the 'My Downloads' folder, and such locations (the crashing and restarting scenario occurs in every situation)

I haven't found a solution as of yet. I even tried ending the process in Task Manager and running it again... with the result of it continuing to freeze and restart even after I run it form Task Manager, until as usual, it suddenly stops crashing and starts working again.

Is there any possible solution to this which doesn't involve any type of System Restore/OS wipe?

Thanks in advance.

P.S. PC is defragged, registry and junk files cleaned using CCleaner and Disk Cleanup, issue still persists. SpyBotS&D cannot detect any malware, and ESET NOD32 cannot detect any viruses or infections either.

I cleared up the Downloads folder and it seems to still happen randomly (when I open Downloads, it's a 50% chance of crashing). It also happened for the first time when I opened a folder (not defualt file, as it is a folder I created for schoolwork) full of subfolders, pictures and tons of Word documents.

I installed an updated graphics driver, which made it occur almost a bit more often than before, but still, even before installing the driver, it was still prominent. Office 2010 was installed maybe 1-2 months before the crashing started.

I'll try that SFC Scannow method now, thanks. And the only maintenance programs I use are:

ESET NOD32 Antivirus
Disk Cleanup
Disk defragmenter
CCeaner

Created 3 folders, one with a jpeg, one with a word doc and one with another folder in it. No crashes now, but I'll keep trying, as it happens at random intervals somehow.

"Verification 100% complete, Windows Resource Protection did not find any integrity violations"