Folders not opening in XP

Hii......

Am unable to open any of the windows folders like MyComputer, My Documents, Personal folders on desktop etc....when i try to open them a message in a popup window appears saying

The instruction at "0x00000000" referenced memory at "0x00000000 ". The memory could not be "written "

Click on OK to terminate the program
Click on CANCEL to debug the program

I've ran my antivirus (AVIRA) and SuperAntiSpyware for any viruses in the system, they've shown some infections which i've deleted, even then the same thing continues to happen....

I am able to open all applications like Google Chrome, VLC player etc from the start menu......

Pls help me guys....this is killing my time