Installed 5.0 on a Vista PC, but the Security Center shows a warning in the tray.
When I open Security Center it says that there is no anti-virus enabled (red box).
But it also reports that Avast! is installed as a spyware scanner (box below).
Version 4.8 reported as updated and installed both as anti-virus and spyware scanner.
Doesn’t Vista recognize 5.0? XP does 
Haven’t tried on Windows 7 yet
Working fine on my win7-32
Have you tried avast repair?
I upgraded without any problems from 4.8 so no…
But this was on Vista, not Windows 7…
Don’t know if the security center works the same way…
Can try a repair and see…
Works fine on my vista 32bit. Try a repair of avast as pondus suggested and see if it helps.
It seems there are some users that have encountered problems when upgrading from 4.8 to 5.0.
I had an issue with one of the scanners not working. If the Repair option doesn’t work you could do a clean install. That’s what I did and it worked perfectly after.