Trojan Agent.FK help needed

A friend running XP Home has had it slow down to crawl pace and I am trying
to help from a distance(not easy to get to PC distance wise). She has Mcafee
and Adaware &Spybot that show nothing. One of my suggestions was to run
Trend Micro online scan, which has shown up Trojan Agent.FK. She got a "non
cleanable in Documents and settings and "cannot access in program files 'cos
it is already in use". A google search really has not come up with anything
but vague reference to this trojan.
I'm unsure that this is the sole problem but I would be most grateful for
some guidance in how to deal with this problem

dfrog