Do not know what problem AVG 7 has given you, I have used AVG for years with no problems and as a freebie cant complain. I installed AVG7 som weeks ago and agin no problems. Anyhow the other highly rated free anti virus on this forum is Avast.
You can set it tp auto-update itself and it automatically updates it's definitions and when it does it tells you "Your virus data base has been updated". You can also download AVAST! Cleaner from the same site which cleans many viruses for you.
avast!, used it for nearly two years, has fielded all nasties received via e-mail and never caused any problems. Antivir is OK but doesn't offer as much. Bitdefender, full version alright, but the free one has been butchered, far too many protection elements removed to make it worth installing.
I'll take a look at Avast as it seems to be used my a few members on this forum, but there's lots of another info to have a look at.
AVG 7 after about 5mins into a scan crashes my PC, it doesnt matter what part of my system I pick to scan, it just does the same thing.
The other common fault, is after downloading it will not let you reboot your PC, and the Windows start disk only lets you boot so far, and then it shuts down again, it cost my son $180 to fix his PC after downloading AVG 7.
Their support forums have got quiet a few disgruntled users, who are not getting much help either.
Avast is definatly the superior program by my reckoning. One thing to be aware of though the latest version will not run if you are using XP with the beta version of service pack 2, you need the full release of service pack 2. Apart from that I have used it for over a year and never had any problems. It always informs me if an email or a file I am downloading contains a virus before it can do any mischief.