Cannot access "my computer"

Hi, I’m new and desperatley need your help!
I cannot access ‘my computer’ ‘my documents’ or ‘control panel’, I can access the internet and office packages fine. I get an error message saying windows explorer has encountered a problem and needs to close down.
I have tried to do a system restore but I get an error message saying it could not be done.
I have checked for viruses and found a dial up trojan which has been deleted.
I went into safe mode and could access the documents this way.

All help greatly appreciated - thanks.

Personally if its that bad i’d do a repair installation assuming your on xp, boot from the cd, there is a fairly comprehensive guide here

http://www.michaelstevenstech.com/XPrepairinstall.htm

This should solve your problem reliativley hassle free.