New radeon hd4850 - windows 7 splash screen freezes

I have installed a Radeon HD 4850 in my Dell Inspiron 560, which has one pci-e slot.

When booting windows 7, the splash screen with the colored windows logo freezes after a few seconds.

I think the problem can be described as "The display adapter that is installed in your computer is not properly processing the video-mode switching that occurs when the Windows logo screen is displayed" (that is from a windows help article for windows 98).

I have searched for solutions; so far, I have disabled the onboard graphics and unistalled the drived for the onboard graphics. I have also tried to boot in safe mode abs install the driver, but the card is not recognized by device manager and the driver installation produces an error "Failed to load the detection driver".

When I take out the 4850, the computer boots fine

Also, I am using a Corsair 550w power supply, 8gb of ram, 2.93 intel core 2 duo processor.

I have this card and it is great. A couple of basic questions:

Did you plug the power into the card?
Did you check the bios after you installed the card?

The only other thing I would check is to be sure that the card is seated properly.

REL

Thanks for replying.
Yes, I made sure the card was locked in and powered several times. I also updated the bios, and looked for any graphics/pci-e options, but found none

The bios indicated that you actually had a card installed? What type connection do you have to the monitor? DVI...right? Let me know if I ask too many questions.

No. I could not find anything in the bios about graphics or pci express. In safe mode, I could not find anything about the card either. I am using a dvi connection. Everything displays fine up to the splash screen logo. It loads for a few seconds then stops. Then you can here the welcome jingle as The account login appears, so the computer is not freezing, just the display.

Ask as many questions as you like. I would like to fix this problem as soon as possible, just haven't been able to find a solution

1- Does your Dell have an on-board graphics card?
2- Did you "disable" it?
3- Did you install the Catalyst drivers for the card?
4- Did you install the "correct" ones? 32 or 64-bit?

And before anyone says otherwise, the 550 watt power supply is plenty

Just trying to help.

Yes, I tried disabling the onboard graphics and completely uninstalling the driver for onboard graphics.

I installed the driver for windows 7, since that was the only choice. The Dell is 64 bit, though.

Keep in mind that I can only access my computer via safe mode when the 4850 is in. Without it, my computer loads up normally.

Thanks for the help. I'm not sure what to do next.

I'm a little bit stuck. Did it come with a manual? I tried looking up your unit and it comes with on-board video, with ATI and Nvidia videocards. It should work. When I installed mine in my HP it recognized it but I did have to make change in the bios to disable onboard video. I did not have to uninstall any drivers.

Can you hear the video card start up? Hear the fan?

I only hear my harddrive and the regular boot up noises. I do not hear any 'new noises'.

The dell came with onboard graphics, however, in the bios, there is no option to disable. So I disabled the onboard graphics via device manager.

When the computer boots up, it makes it to the black splash screen with the colored flag, it glows for about 10 seconds, then a little flash on the screen when it should load the login screen. The speakers make the login screen sound, but the screen stays stuck at the black splash screen with the colored flag, which stops glowing.