I have a problem with my graphics card sometimes not working. It's not limited to a single game.
Would that question belong in Arqade or Superuser?
If the problem only occurs when running games, it'd be on topic here...
But you'll probably get a better answer on SuperUser, where, so long as the question isn't about a specific game, it would also be on topic.
(And if it occurs when running other applications, it's absolutely further into SU's bailiwick.)
It belongs on Super User. Arqade is for questions specific to gaming.
I'm going to disagree with Frank's comment. Even if the issue isn't seen in other applications besides the games you've tried, it's not like non-games are disallowed from using certain features of your video card. Whether at the hardware, driver, or OS level the problem sounds like a general one best suited to SU.
Of course, the specific issue you're seeing might affect my advice here. There are lots of ways it could be "not working" :)