Microsoft released not so long ago huge update to their latest OS Windows 8 which update brings a lot of new features, security updates and GUI changes. For some gamers not all changes might be so optimistic. All these who had Windows 8 and decided to upgrade to Windows 8.1 may have some problems with graphics in games (pink filter, missing elements of environment, missing lights, shadows, etc), slowly working or not working at all games. Windows 8.1 update/upgrade is huge thing and installs a lot of new files and replaces some already existing files and this is the reason why games are not working the way they were before upgrade. 8.1 installer could replace some files of gpu drivers so to fix your problem with games you just need to reinstall or update gpu drivers, if this still will not help uninstall drivers and install them again.
The same goes for problems with other devices after Windows 8 to 8.1 upgrade, mice, printers, keyboards, scanners, soundcards and so on.