My laptop applications wont open & cant download

[tmdrink]

please can you help me, my laptop will not download anything, i cant open any applications or programmes & even my avast wont work - i get a message saying that they are incompatible but they were ok before i ran a scan
it is a hp pavilion laptop with windows 7.
thanks.

 

[JackNaylorPE]

Can you do a system restore to known working state ?

 

[kroobs]

^ try doing restoring to right before the scan.

Also:
What kind of scan did you do?
What is the exact error message that you are getting?