How? Why? No idea. Google told me to uninstall UPlay, make sure all of it's folders are deleted and reinstall it (might need to check the appdata folders to make sure you get everything, post didn't mention it but I assume it's necessary). Ending the WmiPrvSe.exe service is also suggested (you may need to tick 'show processes for all users' for this to show up). Finding and deleting your far cry 3 settings file may also help.