Windows 7 - GeForce 8400GS 256mb pci ddr2

Hi all, I have a problem with trying to install the above graphic card but i'm not too sure whether it's a pc problem, os problem or hardware compatibilty problem. When i installed the card i can't get as far as windows starting up, i can't enter bios or setup or start in safe mode. I've upgraded my psu to an atx 355w so that isn't an issue. I've taken the card back and seen the one i have now working. My bios is up to date and set to auto detect. The card is getting power but as soon as the windows 7 tries to start i get a blank screen. I've been on other forums and have seen others have got this card working on the same pc but with xp, microsoft also say that this card is compatible with windows 7 but i've seen many complain that it doesn't work. I've tried disabling and uninstalling my previous onboard graphics card drivers to no avail. Only other thing i can add is that is as soon as the pc is switched on with the card installed it quickly flashes up the make and model of the card so my pc seems to be recognising it. I've tried installing the relevant drivers without the card installed but i get the obvious message that there is no hardware compatible for the driver. HELP!!!!

Can you be specific about what PSU you have? It looks like it meets the requirement for wattage, but to might not for amps on the +12Volt rail.

Personaly i've had that card in a pc with Seven without any issue...
An Asus based one...

Hi Petey7 and thanks for your reply. I'm a bit of a noob at this so you're going to have to forgive my vague reply. I see on the specs for the psu that i have 2 12 volt lines. 12v1 rated 10a and 12v2 rated 15a.

It's a little hard to find power requirements for a low end card. Lets start off by using the 12v2 rail. The more power, the better.

The power requirements for that card is 350w so a 355w psu shojld be ample shouldn't it?

Wattage wise yes, but Amps are different story. Here are some sources where you can read about the difference between watts, amperes (amps), and volts. The three are related, but different.

Watt - Wikipedia, the free encyclopedia
Ampere - Wikipedia, the free encyclopedia
Voltage - Wikipedia, the free encyclopedia

Just because you have a 355 watts PSU, does not mean you have enough amps. Some sources I;m looking at say 12amps, others say 16amps. either way, the first 12volt rail doesn't have enough power to power the card. The second one might.

scottsman i would go with a new psu atleast 450 you are running a p4 i just gave my cousin the mainboard to my old one Point is 450 would power almost anything on a p4 rig and might be the issue assumming the 8400gs is a decent pci-e card i doubt it is agp

Anyway the more power the better the performance straight up

I'm taking onboard what you're saying about the power and that was my sole reason for upgrading my psu in the first place but doesn't a low range graphics card only draw roughly 60w when idleing?

eVGA is conservative in their recommendations:

EVGA | Products 8 Series Family&sw=

and they want a 350W PSU with a minimum of 18A at +12V. It's not aways safe to just add the capacities of a 2 rail PSU, but I think you're OK.

I doubt that an 8400GS idles as high as 60W. The PCI-E version must, by definition, draw less than 75W fully loaded, and I doubt that the PCI version draws more.

I'm not sure what your problem may be. It sounds like you should have set the BIOS graphics priority to the new graphics card, rather than the onboard controller, but it's not 100% clear from your post that you've already tried that.

The message that you're seeing at startup is from the graphics card BIOS, not the PC. It doesn't mean that the card is working with the system. It is getting power, though.

Many people with onboard graphics seem to have trouble installing an add-on graphics card. That's cold comfort, I suppose.