Next you'll need a folder, preferably on the flash drive, to store the suspected infected files. If you know how to create a folder in Windows, you can figure it out here.

Now open a terminal window: Select Start, Accessories, LXTerminal. A command-prompt window will open. At the prompt, type cd /root/clamav and press Enter. Then type clamscan -r -v --move= path to your new folder /media. For instance, you might type clamscan -r -v --move=/media/sdb1/badstuffinside /media. (Note that there's a space between badstuffinside and /.) Press Enter.

When the scan is over, suspected files will be off your friend's hard drive and on your flash drive. You can then look at them, determine if they're necessary, and delete them. Just don't open them in Windows.

Point your browser to for more on using ClamAV.