If you look at my signature you will see that I have two x64 and one x32 computer.
Other than Acer software on my Netbook all the software on the three computers is the same.
I find that avast! identifies a lot more malware on the x32.
A recent study I read showed that W7 SP1 x64 is a lot more secure than W7 SP1 x32 and even more so than XP.
ISTM that while avast! is a great product that the best steps that that a Windows user can take for security are
In order of importance.
1. Use Windows 7
2. Install the x64 version
3. use avast!
4. Run daily Scans though most people here feel that is overkill.
5. Keep all software up to date
6. Clean your computer's cache, flash files, cookies, temp files, pre-fetch files etc when you are done using the computer for the day.
7. Use anti-malware software along with avast! MBR and SAS are both good.