Big Problem with win7!!! programs wont run, cant save files

Ok guys this is a hard one, I've recently noticed a big problem with my laptop running win7 32 bit, I have tryed everything possible to fix it with no success, the following problems are occouring:

Only certain programs will run, if i run windows games folder explorer.exe crashes, same as if i run performance monitor and other control panel programs, I cant save a file to my computer eg if i open notepad type some text and hit save it just crashes, same with itunes and alot of other software i have, the system is running slower then usual aswell and the only things i have done recently are, a windows update, itunes update and adobe reader update, now ill tell you what i have done to try fix the issue.

I have run ESET Smart security, Malware Byts anti mull ware in safe mode and found no virus / Trojans etc, i have restored windows back to before i done any updates, I've checked registry for exe file association issues ive turned off all firewalls and re-installed most recend windows updates, ive turned off UAC and run a CHKDSC and everything still crashs?

NOTE: im sure its not a file permissions issue as i can save a file i create using photoshop to anywhere on my pc.

Im stuck i normally can fix my issues but i dont have a clue on this one!

I would recommend a repair install first, and if that doesn't work, a clean reinstall.

~Lordbob