Start the PC in Safe Mode w Networking, open My Computer and navigate the the ProgramData or Application Data directory.
Locate the directory with around 7-10 numbers as the name. Open it, note the filename of the .exe inside. Navigate to the Mbam-setup.exe file and rename it to the filename you noted earlier. Then run the formerly named mbam-setup file. It will now run and install.
By nature this infection must Whitelist itself since all other .exe's will be blocked.
I don't know if this works all the time, but this method has worked on the least 5-6 PC's I tried it on.
Hope this helps someone.
Edited by esde, 05 May 2010 - 01:35 PM.