Help repair graphic card(may be hardware repair)

We are going to need the rest of your system specs as well. It could be a power problem or an overheating problem.

That card is simply terrible for gaming so this sounds like a good excuse to upgrade. You can get a card several times better for as low as $50.

Download a copy of CoreTemp. In addition to monitoring CPU temperatures, it also looks at GPU temperature. That will help you spot any overheating problem.

ok.but first i want to say what cause this problem:
i installed "speed gear" software and then my computers hanged, i reseted it,then my graphic card came in 4 bit mode and when i installed it computer could not recognize it.i changed my windows also my driver but the problem still was there.
finally i removed the battery from mainboard and reseted the bios.
then i installed another windows.everything was good since i know this problem that i wrote in first topic.
i changed
my system:
cpu:intel e5200 2.5gh
mainboard:asus p5kpl/1600
graphic card:gigabyte 8400gs
ram: 2gig
power:450w ?

I just looked up speed gear and that software looks dodgy as all hell but I really doubt it could've actually broken any hardware.
Check for overheating like these guys are saying but even if it is the best you can do to fix it is cleaning the card.

hi again,i check my gpu temprature,it goes to 87 until 15 minutes playing in windowed mode of game (flatout and...),but in the full screen mode my graphic card hangs in about 3 or 5 minutes.
i do not think this problem is because of temprature,i think there is something wrong with my graphic card.
plz do any body knows how can fix it,may be i can repair it if u say where the problem is.
thanks.

If your graphics card is dying, there's nothing you can do to fix it. Dead graphics card is just a good excuse to buy a new one.

87 degrees is quite high and it likely gets higher when pushed to full screen. It is overheating. Make sure the fan is working. If it is try cleaning the card out well as cards can accumulate dust that will prevent proper cooling. If that doesn't work it's time for a new card.

If it is the one in the pic then get a cheap bay fan to blow cool air on the card and get a tube of arctic silver5 to replace the dried out crap they use on most cards. Thermal compound can dry out over a few months if it gets very hot so new compound in addition with better airflow will help your card. All together it might cost $10-$15 but if the card is way past repair don't count it as a loss use can still use the bay fan with the new card. I use a vantec duel 80mm with my 9800gt and my 8800gtx so both cards (using one or the other) don't go over 60c under load.

i have done what all you said but problem still is there.
i've played most of the games with this graphic card and there was no problem before even when i was playing for more than 6 hours,
so i think my graphic is somewhere between earth and sky,
i have noticed that my graphic card still has warranty,so i want to send it to warranty.
but another question :
do you think that i write all the thing that is happening or no (they will know the problem themselves)?
++++
sorry for my bad english.
thankx

+1. Something like this should help. If not, then send it back to the manufacturer. They will have you tell them what the problem is as well.

yeah that works well we did the same with some old 9500gt with silent heat sink --stick a fan with 1 or 2 screws just hook it on to the hs and let it cool  

Na they won't know plus they are obligated since the warranty is no voided so good luck and maybe you will get a newer model hehe.