Internet Explorer Issues

I had a Trojan virus which I think got into IE. I have Norton etc and have got rid of the virus but IE I think is keeping my PC busy as it wont idle and the PC has slowed down and is chuntering away as if it workin on something.

I haverun Reg Mechanic which has repaired lots of errors but has identified 2 errors it cant delete - 2 keys to do with IE. I have tried to delete or change keys but reg edit wont allow it.

I am sure these keys are the cause of the issue - how can i change or delete them?

their value is:

"%ProgramFiles%\Internet Explorer\IEUser.exe"

Help!!!!!