Annoying warning sound on high ram/cpu/overheating?

Hello,

so basically my friend has the Fatal1ty FP-IN9 Sli motherboard, and when ever he starts up a more demanding game(Borderlands is the latest example) the motherboard starts playing this really loud and annoying warning(?) sound, my guess is that it's because of high ram usage(90%+) and the motherboard tries to warn you because if he quits the game(and thus RAM usage lowers) the sound goes away.
He is using Windows 7 and since I know that in Win7 the OS tries to 'keep' the most used programm files in RAM for faster access, so that the high ram usage isn't really an issue.

So that's the story so far, the question is - How to disable the sound since it's impossible to play with it playing(might not be the best word? ).

So far I've asked him to check BIOS for anything that would resemble the sound warning and see if it would disable it but he didn't find anything relevant there.
I've also tried googling the issue but all google comes up with are reviews of the motherboard or countless topics about how Win7 uses a lot of ram.

Regards,
Krisjanis Zvaigzne

Check the GPU temperature as well under load, using GPU-Z or other program.

Quote from PC Wizard '09:
Mainboard :Abit FP-IN9 SLI(C55-MCP51)
Chipset :nVidia nForce 650i SLI SPP
Processor :Intel Core 2 Duo E6300 @ 1866 MHz
Physical Memory :2048 MB (1 x 2048 DDR2-SDRAM )
Video Card :NVIDIA GeForce 9600 GT
Hard Disk :SAMSUNG (80 GB)
DVD-Rom Drive :STADABU 270H2BK9 SCSI CdRom Device
Monitor Type :Samsung SyncMaster - 20 inches
Operating System :Windows 7 Professional Professional 6.01.7600

Now as far as temps go they are ~50 degrees Celsium when idle(firefox open, skype call) and jump to ~65-70 in-game