Windows 7: Windows Explore .exe not responding

My computer is becoming increasingly slow and unresponsive, after running several virus scans and degraments also ive rebooted my system, Now i've found that the entire computer freezes and comes up with "windows .exe not respinding, this program may respond if you wait" but it doesnt, my computer runs fine if i start it in safe mode but i'd much rather fully resolve the problem. please help !

Give this a try: How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7