Down to the jist of the situation => Go to My Computer => (C:) Drive (or wherever you installed the game) => Program Files => Electronic Arts => Crytek => Crysis 2 => bin32 => Crysis2Launcher.exe
Yes Crysis2Launcher.exe, not Crysis2.exe
And your patch download should start patch v1.1 and there you go. I apologies in advance if someone else has posted a similar topic but I looked and haven't found this specific issue anywhere. My copy is a retail copy, I have been trying to play the game from steam by adding non steam game etc...and stumbled upon this solution, so I hope this helps.