A while ago a DRM issue struck all PC owners of Gears of War, making the game unplayable if the system’s date was set to anything after January 28. Epic announced back then that they had no idea why something like that happened, but they promised to deliver a fix as soon as possible. Today is that happy day for all PC gamers, who can now change their system dates to the real one.
Therefore, you should go and download the update right away – Epic and Microsoft have posted lots of mirrors here, just to make sure that everybody grabs the fix ASAP. Happy playing and let’s hope we won’t have expired certificate problems (or other DRM-related ones) for Gears of War and no other games.