Respital

Hey everyone, I'm been having some problems with my 8800GT it's a guess but i think it's most likely the problem. Now here's the situation, often when playing games like GRID or even The Sims 3 on default settings my GPU temp raises EXPONENTIALLY (as high as 99 degrees C), before you ask I've already blown the dust out of it and that's not the problem. Also sometimes while alt-tabbing i encounter the error shown in the first picture and i never get a pop-up dialog nor do i know where to find it.

My rig is in my sig, as for other details i run dual monitors the Samsung and a no-name and my drivers are up to date.

Thanks guys!

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Winner of Photo Tourney: Twilight
/My Rig:/
/Case :/ Antec Sonata III
/Power Supply :/ Antec Earthquake 500W
/Motherboard :/ Gigabyte P35-DSR3
/Processor :/ Intel E6850@3.4Ghz
/Ram :/ Consair 2x 1 Gb 800mhz
/Video Card :/ Zotac 8800 GT
/Monitor:/Samsung T220 w 20 000 : 1 Contrast and 2ms response time
/3DMark06 Score :/ 11730