Have you recently changed the settings on DEP for your computer ?
Go to this page to access DEP settings location and ensure it is set as in the screenshot below http://windows.microsoft.com/en-us/windows7/Change-Data-Execution-Prevention-settings?SignedIn=1
hey. i uninstalled realplayer (just on a whim,always took ages to load) and left my pc alone. now going back flash seems to be working fine,no dep blocking. i did check the settings bit but it wouldnt allow me to change them to allow flash. looks like i dont need to anyway. thanks for all your help. am doing another mbm scan just to be on the safe side tonight. and will do an avast one tomorrow.
thanks again. ;D
Glad all is well now 