I have spent the better part of the day trying to install Avast Free 5. When I first tried to install I kept getting a BSOD and PC shut down at login screen. I did a restore to before Avast 5 and PC loaded OK, I uninstalled 4.8 and tried to install 5, Everything seened OK but I have no predefined scans, and when I try to Run a custom scan I get error message. "Unable to start scan. An attempt was made to load a program with an incorrect format. Can anyone help I should mention I am running Windows 7 Home Premium