justbigbs

(Right way) clean you temp folder/temp internet folders. SCAN YOUR HARD DRIVE FOR BAD SECTORS. check for recently installed programs that might be causing it, uninstall it and see if it works, there a few programs out there that slows down folder browsing, one category is virus scanners

(guesses) select "do not cache thumbnail" in folder options, I doubt this will work, but worth a try, if none of that works

(2nd try) try ccleaner run all scan/cleans and see if that work, if all else fails, if you have a spare hard drive, do a clean windows install to isolate hardware possibilities, if that the case, I'm afraid you'll have to clean out your other hard drive and install new windows minus the program/files causing your problem