Comodo AV is still only a beta release so likely to have a few as yet unaddressed problems or 'bugs' -- for that reason alone I would not advise using it. Beta software is best left to those who have a spare system to run it on as it's more likely to mess it up.
ClamAV is a finished product (not beta), so I would recommend that over Comodo, except for one very important point -- ClamAV does not have a 'real time' on-access scanner which prevents you from triggering a virus when you attempt to open an infected file. So you absolutely must remember to manually check all downloaded files with the right-click context menu before opening or running them. It's a big risk if you forget.
My own recommendation to you is to forget both of those. Download 'Avast Home Edition' which is free, updates are free, and more importantly it stops you opening infected files (real-time on-access protection) and lets you run a scan whenver you want, either on a file, a folder, or the whole system. It's not a resource hog either. Get it here:http://www.avast.com...ast_4_home.html
Edited by pip22, 19 November 2006 - 12:35 PM.