Windows 7 not recognising Avast!

[Ashwyn]

I installed Avast 7 Free Edition on my Windows 7.For some reason the Windows 7 Security Center does not recognize Avast.It says "Windows did not find any antivirus program". This never happened when i used other antiviruses..I even Reinstalled Avast and did a fresh install and restored my system using System Restore to a ti me when it was normal but in vain.Plz any help would be apprieciated.... 

[DavidR]

Other than windows 7 saying it doesn't find an AV, is avast running properly, e.g. showing Secured when you hover over the avast tray icon or open the avastUI ?

If so this is more of an issue with win7 than with avast.

Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?

Using System Restore can have some unforeseen consequences.