What are your specs? (more info !)
What games are U trying to play?
Do you get any error messages?
Do you have Direct X installed?
Check at start>run>dxdiag
Do you have a video card? If so, do u have drivers for it?
Right click My computer, go to Properties>Hardware>device manager>Display adapter
That is the name of your video card.
Write, and we'll see.