philo said:
have him run his virus scanner at once
You can get free ones, so it doesn't even have to cost anything
to check for malware.
The free version of this, runs in Windows.
http://en.wikipedia.org/wiki/Malwarebytes
The free version of this, boots standalone and has its own OS.
It can scan all the partitions on the disks. If the modem/router
is already running and supports DHCP, it also downloads the
latest virus definitions.
http://support.kaspersky.com/faq/?qid=208282163
"Iso image of Kaspersky Rescue Disk 10 (196 MB)"
You burn a CD with that and boot the computer with it,
then select the partitions to scan for malware.
Paul