use task manager with the following program:
<avast program directory>\ashquick.exe [location to be scanned]
so lets say that you have a default install and want to scan the c drive:
c:\program files\alwil software\avast4\ashquick.exe c:\
it will pop-up and window and begin scanning... if you really wanna make it interesting you could grab a program like Firedaemon (
http://www.firedaemon.com/)... this program allows you to setup ANY executable as a system service so the scan would work even if you aren't logged in... (I'm not sure if the windows task manager does this anyway, I've never checked and I'm not about to waste my time trying to find out)
Noticable Caveats: it doesn't seem possible to control which files it scans (so the scan will check every file type, which can take a while)... albeit you can specify multiple directories to scan:
c:\program files\alwil software\avast4\ashquick.exe "c:\program files" "c:\windows" "c:\downloads"
so you could just avoid the directories that contain mp3's and other non-infectable files etc... hope this helps as this is what I'm currently doing and it works really nicely...