I think what you are asking for is a game maker program, not a graphics library. I say this because almost every single graphics library is free. There are also many free graphics engines out there, but regardless you have to know how to program in C or some other programming language to do the backend stuff.
Now there are some game maker programs, the most noteable is called "game maker". However the full versions of these programs are usually not free and they aren't very cabinet friendly. (Can't redefine keys, some of them rely on mouse input, ect...)
I'm not discouraging you, I'm just trying to make you aware that there isn't an "easy" way to make a game. It still requires a bit of programming knowledge and some hard work.
But with that being said. It's video poker right? You don't need a graphics engine. You can put up images of cards and simple stuff like that with the built in windows gdi and any programming language. You could do it quite easily in vb, visual c++, java or ect... Since you aren't dealing with high frames of animation or anything like that, simple blitting to the screen should suffice. Also you could probably do something like that in shockwave or flash. It's not as "programatic" as visual studio languages if that's what you are worried about.
Hope that helps.