First post here. So, hello. =) Hope you guys can help me out.

I bought an XFX 6600GT the other day.
256mb
PCI-E x16
DDR3

I put it in, loaded my boot to PCI-E.
Everything seems okay. I install the drivers that came with the disk, and restart.
I think "Okay, ill see how it runs".
So I open WoW. Within 5 minutes of opening the game, it crashes and my computer locks up.
I restart, and I see some strange characters at boot. alot of these: á
Load up windows, and the colors seem strange. I downloaded the latest drivers and see what happens with WoW again.
Crash, and same strange characters/artifacts on boot.
This time though, when windows finishes loading, my screen goes black and gives me "No Signal".
And thats that. I cant seem to get it to load windows without myself getting a No Signal error.
The computer seems to keep loading, but the card's fan turns off and theres no video.

Any help on this would be greatly appreciated.
My computer specs:
ASUS m2npv-vm motherboard
400W PSU
1gig ddr2 667 RAM
Sempron 3000+ 1.8GHZ
and of course XFX 6600GT 256mb DDR3 PCIEx16


And yes, I have tried:
Underclocking the card
Checking temperature of the card
(When the fan is on, it doesnt seem to go any higher than 55 degrees)

Thanks guys.

It could be either your psu or drivers or both.
The card requires about as much power as a 7900GT (48w idle)
psu-enough power and does card require connection to the psu?
drivers-which are you using?
info on card:
http://www.xfxforce.com/web/product/listConfigurationDetails.jspa?productConfigurationId=950

The PCI-E version doesn't require a direct connection to the PSU. It takes all its power from the PCI-E slot. But do make sure you have a PSU putting out at least 16-18A on the +12V rail.
Make sure you install the latest drivers for your motherboard and your video card. Also, use the NVIDIA Control Panel to monitor the card's temperatures. It might be overheating.

Update:
I can load windows using the card IF I select VGA Mode from the XP boot list.
Obviously the colors are ****e and the resolution sucks.
Anyway
I can uninstall the drivers and restart, and everything works normally again until I re-install the drivers. Then I start getting the "No signal" error on windows load again.
Ill try update my motherboard again.

How can I check my PSU gives the required wattage on the 12v rail?
Dont really know much about them

Thanks again guys =)

It isn't your powersupply or you motherboard. The video card is dead. Those symbols and the funny colors during your motherboard post means the video card is dead.