If you have problems running Street Fighter X Tekken this is most likely a problem with Games for windows that gets installed when you install Street Fighter X Tekken. Go to uninstall programs and remove Games for windows live next install a newer version from here http://www.xbox.com/en-US/LIVE/PC/DownloadClient
after installing this newer version run the game again and it should work with no more issues.

Games For Windows Live 8.1
Games for windows live internet connection errors or games like Street Fighter X Tekken crashing on boot up or black screen do the above to fix this issue.