ok thats actually good news...there's your problem. So...go into UAC and turn it all the way off manually (so control panel, security, action center? (its that on win7) and then change user account control settings. Then go to never notify me when.
Reboot your computer. ***must reboot to set UAC as off***
***remember to run all of these exe's as 'right click, run as admin'***
Install mtw2 into a folder called c:/games (this eliminates any chance of virtual store)
Install kingdoms to same folder
Install patch 1.05 (do run as admin here)
Install ss6.3 to the c:/games path (may have to manually enter, browse for it) (remember to do run as admin)
Run ss_setup.exe (as admin) ***not totally necessary but better safe than sorry***
Install ss6.4 (remember to do run as admin)
Run ss_setup.exe (as admin)
Try to play the game
report back

good luck!
-losty-