Multiple programs won't open .NET runtime error

Hi guys hoping someone may be able to help me. I am having multiple programs crashing when trying to open them for example Norton Ghost and My Movies. I have checked in the log and they are all getting the error .NET Runtime version 2.0.50727.5477 - Fatal Execution Engine Error (6F70FB66) (80131506). I am running Windows 7 Media Centre.


Thanks in advance for any help
Erica