First try a simple reboot, this has solved many weird problems!
Also Right on the icon and click on Run as Administrator.
If that fails, disable your security software. I used to have this problem with Norton and DBPro, often it would take up to 30 minutes to launch and sometimes not at all.
If this fails, then do a control alt delete and see if the AppGameKit process is running at all. If it fails to launch once, but still remains in memory then the chances are further launches will fail, you can either force the process to close, or reboot you PC to ensure it's not stuck in memory.
If you have any kind of background programs running (other than standard windows processes) then close them, or if you are willing do a diagnostic startup and uncheck all the background apps you don't need to load. To do this use System Configuration, there's an MS document on how to do it
HERE be sure you know what you are disabling if you are unsure then don't disable it.