Hi
Since about a week ago, every time Avast updates it asks to be rebooted.
Is this correct (didn’t happen b/4)?
Thanks
Bob.
What is your OS ?
Operating system restart needed by avast message - First check the contents of the C:\Program Files\Alwil Software\Avast4\Setup\setup.log file, which should show you why it thinks the reboot is needed.
This could be solved, in some systems, by deleting the file C:\Program Files\Alwil Software\Avast4\Setup\reboot.txt
If that doesn’t resolve it check this:
You can also check this registry entry (right after computer restart):
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager, if it contains “PendingFileRenameOpertaions”.
Check its contents and if there’s only “reboot.txt” from avast4\setup folder, delete PendingFileRenameOperations, don’t delete any other key.
Back-up (export) the registry key before you edit/delete, just in case.
There is however, a problem for some users that have used a tweaking program which has an impact on avast. See 8,3 Tweak issue - Check out this thread and see if some of the possible solutions can help you too.
http://forum.avast.com/index.php?topic=28199.0
Many thanks for the fast response. 
Will have a look when more time available (not confidant with the registry afraid).
Sorry, forgot to mention my OS = Win xp pro.
Thanks again.
No problem, let us know if you need more help.
Welcome to the forums.