Video error running Mafia I

if anyone could help me on this, it would be great!
I don’t really know how to call it, but some frames seems to not be processed or whatever, so they get really annoying while I’m playing (this happened with Iron Man too), even in the Menu of the game there is errors
my video card is an onboard one, and only have Pixel Shader 1.1.. maybe this is the problem? the strange thing is, I can run the game, but it gets like that:

anyone knows why this is happening?
ps: sorry about the english!
Answer #1
i think you answered the problem yourself, onboard gpu that isnt meant to be used for games.
Answer #2
The last time that happened to me was many ears ago, the problem was the video card, it was really weak.
Answer #3
hmmmm got it.
both Max Payne and GTA work fine here, so that’s why I had this doubt, ’cause they’re all similar graphically to Mafia.
but, thanks guys!