If he can boot into Windows have him update his virus defintions and scan his h.d.d. for viruses.
Have him try Housecall also.
http://housecall.trendmicro.com/
Other good tools to use is Adaware http://www.lavasoftusa.com/software/adaware/
and Spybot
http://beam.to/spybotsd
Make sure you update both tools before running.
*edit
You can also put his h.d.d. in your computer as a slave and run scan disk and scan for viruses with your anti-virus program.


