Virus Help for - JS/Exploit-ScriptSrc

Please help!!

I am a new user to the Community Forum and need someone's help.

My new Dimension 4600 (purchased in 12/03) caught a virus, I believe a cookie from somewhere and that my McAfee anti-virus tells me it cannot delete...

McAfee first asks what version of the DAT.FILE do I have before their site can help me with a Microsoft patch...

Can someone please tell me what I have to do to remove?  MILLION THANKS..