please help> freezing computer

need some help with my freezing computer. ive got
power supply:: 450 watt
motherboard:: bio-star m7ncd ultra
processor:: amd 2600
video card:: geforce 6800 gs 512 ram by diablo-tek
hdd:: 55 gig
memory:: 1 gig
onboard sound and network

.........im having problems with playing even the simplest of games, even some screensavers, the comp will always freeze with all my games except CFS 1 (i get 60-90 fps with this game). the cpu temp when freezing is between 120 F - 130 F while idle 110 F - 115 F. my cpu fan speed is a steady 2400 rpm, but i dont think that these temps are too hot.. i currently have updated drivers throughout the comp. all default bios settings. I have tried everything that i could think of, so if anyone could help, i would be greatly appreciated.

Could be PSU but I'm leaning more towards either drivers, or another piece of hardware such as the card itself or RAM. What screen-saver are you using? What brand is your PSU? Any 2-D games make it freeze?

My psu is a Ultra model::win-400ps.
sorry i thought it was a 450watt/...
not sure if its relevant...but it says pentium 4 on the side...i am running an amd2600
i have not overclacked anything/ its all original settings/ last night i tried to play brick blaster then it froze-up/ i dont have pci....its an apg

my settings are all correct, nothing else i have says im running a pentium 4, the stamp just brought curiosity. mobo, and psu has been used for 2-3 yrs, everygame and all applications are all set to amd 2600.

ive also noticed another thing, i had to underclock the cpu to 1250, to keep it from locking up inn combat-flight-sim 1, even though the cpu has not ever overheated could that be a sign that my psu is quitting on me, or are my problems more than expected??

meanwhile, i thank the time all you have set aside for me

Most likely is the problem of your mobo or the CPU cooling, the abnormal sound would be the alarm of overheated but you may check with the mobo manual to see the meaning of long siren sound means. Please check if the CPU cooler unfortunately the cooler is loose, or if you have additional powerful CPU cooling available for this CPU, you may try to change the cooler to see if you can overcome the overheat problem.

I didn't use AMD cpu in past 5 years and have no idea on the reliability of Bio-star mobo so the problem other than cooling may be not helpful for you.