Installed avast 5 free on a laptop I normally do not use, it is fully up to date (100325-1 as of this writing), and microsoft security center reports I am out of date. A quick search of previous topics reveals most questions asked refer to avast 4.8 instead. Any help or step-by-step trouble shooting?
Go to PROFILE then Modify Profile then Forum Profile Information then update your Signature: with information like my signature as this helps the helpers offer pertinent advice.
Check the system date and time to make sure it is correct.
It doesn’t really matter that much if they are 4.8 related as I believe most of the suggested solutions are the same for both.
System date check as YoKenny suggests.
If that is correct - Try a repair of avast. Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button and scroll down to Repair, click next and follow. This has in the past resolved this out of sync issue between reported and actual virus definitions version.