Launcher.exe is missing from the folder that you installed the program in(probably Sudden Attack). Click Browse and find your launcher.exe. Besides, your anti-virus might also be the cause of the problem because if your anti-virus had deleted Launcher.exe, the same message will appear.
Also, to turn off UAC on Windows Vista, go to Control Panel --> User Accounts and Family Safety --> User Accounts --> Turn User Account Control on or off --> Tick the box (Use User Account Control(UAC) to help protect your computer --> Click ok.
Hope this informations helped you in any ways.