If your using a sata1 drive with a sata2 controller setting the 150mbs jumper might help stuttering, If its a ide drive, some mother boards don't like cable select, setting master/slave can smooth things out. sometimes the other way around.

you should check the jumpers on your drives, see if anything is overheating, and make sure everything is getting enough voltage.

If your computer is set up properly, and is 100% stable, you shouldn't get any stuttering or skipping.

Is the video card good, my dad mainly wants to be able to play the flight sim X on it or should go for an 8800.

GordoMIM

You can play Flight sim X on max 1280x1024 with a 8600gt but only at 23fps, maybe overclocked you might be able to get more I haven't tried that yet.

You could remove the face plate and screw a 80mm fan into the heatsink, and replacing the original thermal paste with some as5 usually helps.

But which one is better, cause I'm not going to be oc'ing it at all, so obviously the gts will be better for another 20-30 dollars.moo111

If your not overclocking, then get the gts. for 20 or 30 dollars its worth it.