I have a dell inspiron 518 with core 2 quad 2.66Ghz, 1TB, 6GB DDR2 ram, 1024MB nvidia geforce 9500gt but whenever i install windows 7 ultimate 32bit plus the updated drivers of the card, the computer displays 512MB instead of 1024MB. However games like arma 2, crysis 2, battlefield BC2 or wheelman donot lag or get stuck while playing. What could be the problem?

Your PC RAM memory is defective, replace it and your computer will boot up again.

Maybe the thumbnails on windows are disabled.
Google for it.

NVIDIA 9500GT DRIVERS DOWNLOAD

Hope it helps! Good Luck!
CreativeTECH

There should be no reason why this card won't work with Windows 7 32bit, it could be as simple as your Graphics drivers are out of date. I recommend downloading the latest Windows 7 drivers for your card at the Nvidia website.

Just remember graphics RAM and SDRAM are two completely different things so they don't add up.
As far as I know the 8400GS is a 256MB card.

Contact Gateway and have them send you a recovery disc. This might help you access the recovery partition if the recovery software was damaged somehow.

your powersource has blown out. get a replacement, only $40CAD average for repair

you dont in most cases. Install Ubunto operating system, its free only takes minutes to install, it looks just like XP or VISTA. then run your program and flash it. Google "Ubunto" or linuz download.

remove the door and put in greas

If the resources for the machine are a quad core processor with 6 gigs of memory and a 640 gig hard drive, then not at all. Are you running Windows Vista 64bit edition? Ive had issues with itunes running properly under this OS. Grab the latest copy from Apple's website (make sure you uninstall the old copy first, do not install the new copy on top of the old one). Check for any Windows updates and install them before installing the new itunes.

This could simply be an issue with you bios. Flash to the latest bios version.
From the site it looks like the Mars has had some bios issues in the past.
Nice setup btw