I am NOT having this problem, but I’d like to comment about it anyway.
Although I think this is a conflict more related to Windows Activation than to Avast, I indeed think that the bottom line will be that some users will stop using/installing Avast and they will start recommending other security solutions.
I am GUESSING that the problem is presenting itself in “new” installations of Windows (Vista), which may include “Factory Restore” situations.
Vista users MUST update all the Windows “Critical” updates, including SP2 and all the ones coming after SP2. This is a Microsoft’s requirement, not just from Avast (SP1 not supported by Microsoft anymore).
In “new” pre-SP2 (RTM/SP1) Vista installations, the users MUST run the Windows Update application several times (rebooting between each) BEFORE installing anything else.
Users aware of security issues tend to install security tools (like Avast) as their first program just after installing Windows. This, in the case of Vista, is “a mistake”.
As oppose to XP, generally speaking, Vista newer updates do NOT include the “older” ones. So, to install SP2 for example, the RTM “user” needs to install all previous updates first, including SP1. SP2 can’t be installed directly over RTM.
Using the Windows Update Control Panel in Vista, the user needs to reboot after finishing the “new” installation, and run the “Check for updates” once. After the updates are applied, reboot. “Check for updates” again, and reboot after applying them. Repeat until no new updates are found.
When no new updates are found, check that Windows Vista has the SP2 installed (Win. Ver. 6002…). Only then check that Windows is already validated (recognized as a valid Genuine installation).
So the steps should be:
1_ update all the necessary Windows updates first (several times and reboot in between);
2_ Validate Windows (and reboot);
3_ install security tools (and reboot);
4_ add/install optional (not indispensable) drivers, like the printer;
5_ re-check for Windows / drivers updates;
6_ install other tools.
If Avast was installed before SP2, the user needs to boot into safe mode, uninstall Avast, reboot and try to update Windows and validate it. Only then, Avast may be installed again.
This is not a “solution”, but a “workaround” to reduce installation problems.
As I mentioned, Microsoft will not be “paying” for any of these “validation” problems. Even if Avast may not be the main problem, Avast will “pay” for it, unless Avast Team can come with a workaround that will work for any (less experienced) user(s).