@DragoXP "everyone complaining about problems with the new Avast 5 dont know how to properly uninstall anti-virus software. Every anti-virus program leaves parts of itself behind on the disk and in the registry, all you have to do is go and get rid of them. If you dont want to do it manually, then use a free utility like Ccleaner. Im running xp home sp2, no problems, and Avast 5 runs faster than it ever has. I have a 5 year old computer single core chip and only a gig of RAM. Avast's uninstaller is one of the best i have come across as it does get rid of all of the important stuff, though maybe the new installer for avast 5 is referencing these registry entries that are left behind and by them already being there, they are skipped and their settings are incompatible with the new version."
Drago, you couldn't more wrong if you tried. I'm running Windows XP SP3. You're not the only person who understands how to properly uninstall software. Avast 5 is very unstable as referenced by many Windows XP users here. I properly uninstalled Avast 4.8 using the Avast uninstall utility as well as running CCleaner and ensuring all references to Avast 4.8 were removed from Zone Alarm. As far as my computer knows, Avast 4.8 didn't exist by the time I installed Avast 5.
Count yourself lucky that you can run Avast 5 in its current state under Windows XP. But get off your high horse and lose the obnoxious attitude.