Yes, as long as the live CD you use has software on it capable of finding and removing whatever specific malware you've caught - check to make sure you've got up to date virus definition files, for example.
Or you could boot to a live CD and download something then, while it's running (but obviously would have to re-download every time you boot).
Or get any old live CD and make sure you have all the AV stuff you need on a USB stick.
Have a look at the questions I've linked below, which investigate a similar theme and have several suggestions that I think may already provide a useful answer for you:
http://superuser.com/questions/88924/anti-virus-live-cd
http://superuser.com/questions/130389/live-cd-with-good-anti-virus-software-to-scan-repair-windows