I'm surprised no one has mentioned this yet.
Got a spare USB thumb drive? You frequent CF.org of course you do.
Create a easy multiboot drive!
Grab the newest version of YUMI
Select your drive.
Scroll down the list and pick an antivirus (I recommend AVG).
Click "download the ISO" after clicking the antivirus of your choice.
Select the downloaded ISO, click create.
You can now scan the windows partition with AVG via linux running off the thumb drive. Plug the laptop in via ethernet and you can also update the virus database.