PC Specs

Intel E280 Processor
Asus P5SD2-VM MOBO
1GB RAM
160 GB Seagate HDD
500w PSU

WinXP SP2

TDK DVD+-R
Samsung Super-Multi

LG W1942T LCD Monitor
1440 x 990 RES

Hi I bought a PC few months ago with that specs, as i want to improve its performance a purchased a 8400GT Nvidia Card which is 512 MB a month after i bought the computer
But then, the color and graphics and my desktop improved but whenever i play a video and play games like rocket mania, secret of margrave manor etc. (popcap games) and games like nfs underground and GTA San Andreas...
my system hangs and then reboots, sometimes the blue screen of death appears, so i decided to return the VC i purchased, after trying for four time (getting it replaced with brand new same make same model) the condition has not improved
then i decided to purchase a different model this time a 8500GT which has 512MB and 128 Bit.

and yet nothing has improve, still cant play games which needs hardware accelaration etc...

what could be the probleM?

thanks for helping....

under display settings i am stuck on default monitor,800by600.I have tried all the easy problem fixes,cant go into advanced mode is grayed out to up date driver.I have a gateway laptop with windows5.1 service pack9build (2600)

dipsoul;

Did you disable the onboard graphics in the system bios when you installed the add-on video card?

Do you have the latest drivers installed for the current card, after uninstalling the drivers for the other video cards?

Does device manager still show the onboard video as active (enabled)?

DANLEFF:

Thanks for replying and sorry for the late reply.

Anyways, yes, ive done those things.
and the device manager dont longer display the onboard video

what i am thinking right now is that the PSU may not be sufficient... but i dont know how to know the specs/capacity of my psu and what requirement my card needs...

btw, i experienced this last weeks...
samsung drive wont work properly... then i disconnected the tdk drive and for a week now, its perforwing well...

that why i think there could be some sort of power shortage...

my vendor said that my PSU is 500W, which i think is sufficient for my hardware...

sorry for the long read.. What to you think? Thanks!

500 watts seems like it should be enough with what you've described, as it looks like that model only needs 300-350 watts. But if you're having problems with other decives not functioning, that might be it. Before you go off and buy a new PSU, you might just want to retry doing it all.

Try installing the onboard video, switch to using that one, disable the video card, remove it from the Device Manager, remove it from your machine, and start from scratch. Yeah, it's a bit of a pain, but at least you get a chance to fully retrace all steps through the process. Also make sure that you have the most up-to-date drivers from the manufacturer's web site. Also update your BIOS; not sure if that would help, but you'll be able to scratch that off your list.

Worst case scenario, you could try to use a PSU with more power. Check out dealnews.com for PSUs. They post the biggest sales out there. I know NewEgg.com (Feb. Sales) is having good February sales, which includes PSUs.