Hey guys. I just installed the Gigabyte Nvidia GeForce 6600GT 128mb AGP yesterday so I could play Call of Duty 2 with better FPS. After upgrading it from my old FX5500 from MSI, It wouldn't boot up and couldn't detect the video card. I have never ran it before and I don't know if it's a power issue because my power supply is 350w and I am sure that's enough power. But if I set the AGP to 4x, it would boot up, but after the Windows logo, it would do something similar to turning off the computer. Please help! Do I have to return it to Gigabyte?

Here are my specs
Intel Pentium 4 3.0GHz
ASUS Motherboard P4P800 Deluxe
MSI Nvidia GeForce FX5500 (current video card)
Windows XP Professional SP2

Let's start with the simple stuff, you do have the molex connector pluggied into the back of the vidcard, right?

After checking out whether your connector is making contact, you might want to answer these questions. Were you using the MSI drivers with your old card, in other words, the ones from your CD or what you may have downloaded from MSI? Did you remove these drivers before putting your Gigabyte card in? MSI does some nifty things with their drivers but they need an MSI card. They will often not work with a non MSI card even though each is based on the nVidia universal driver sets.

Yes, and run Driver Cleaner Pro after uninstalling the drivers http://majorgeeks.com/Driver_Cleaner_Professional_d3214.html in safe mode. Don't let Windoze install the drivers when it asks to, install them yourself.

Originally posted by Relic:

"Let's start with the simple stuff, you do have the molex connector pluggied into the back of the vidcard, right?"

Yeah, the connector is lined up as the other colors. And Sampson, I tried to use a new motherboard for my 6600 and it didn't work. I didn't have MSI drivers there, but I was 100% sure I removed the MSI drivers on my current computer.

Try unplugging everything you don't need to boot, CD/DVD/floppy/sound card/case fans, then see if it boots.

350W is the bare minimum that card will run with, so depending on how weak the PSU may be, or how much you're already drawing off the 12V rail, it could be the PSU. When you unplug everything you don't need, make sure the card is on it's own molex.

The video card would boot normally, but the monitor would just flick off after the Windows XP logo. So I tried what you said, but it still won't boot.

Okay, time to play in the BIOS.

Reboot and go into the BIOS, make sure that these settings are disabled:
System BIOS Cachable
Video BIOS Cachable
Video RAM Cachable

Set your AGP Aperature Size to 128mb

Make sure that AGP Fast Writes are enabled.

If the AGP Fast Writes are already enabled, and it won't boot in AGP8X, disable them. Your card should be able to boot up in 8X mode, you have an 8X AGP slot.

Might also be a good idea to update your chipset drivers: http://downloadfinder.intel.com/scripts-df-external/filter_results.aspx?strTypes=all&ProductID=1049&OSFullName=Windows*+XP+Professional&lang=eng&strOSs=44&submit=Go%21

Also, if you can boot into safe mode, right click the desktop, click Properties/Settings/Advanced/Monitor and then check the box that says Hide modes that this monitor cannot display

I cannot boot into Safe Mode either. It hangs while loading the files. I think I should return this to Gigabyte and get a new video card since I have 1 year warranty left. Thanks for the help anyway, Relic.

You're welcome, and when all else fails, RMA.....