Rebooting problem after v-card install...

The most likely suspect is power. Either your psu can't deliver enough along the cables you've chosen, or it can't deliver enough period, or you haven't installed the power connectors correctly on the card.

If you have another psu to swap in, that would be a good idea.

PS, I can't find a review of that particular series psu anywhere. The 4780 is not listed on the AMD web site. And the Asus site just won't finish loading its home page lol.

[The other far-out suspect is your mobo and vid card not getting along. I'm presuming the x800 was PCIe 1.0 and the 4780 is PCIe 2.0. This is not supposed to matter - the 2.0 device should negotiate correctly with the mobo to establish a 1.0 connection, but . . . Anyhow, I'm frankly tired of waiting for the Asus web site to respond.]

According to newegg, that card has two 6-pin connectors and 54A on the 12v rail. It should be more than enough. Sounds like a driver or OS issue to me. It can also be a GPU issue. Perhaps you might want to uninstall the old drivers for the x800 and allow Windows to run its default display driver and then install drivers for the 4780.

Thanks Twoboxer & Skolpo for your taking the time to try & help me. Here's an "update" on my situation.

Twoboxer : I double checked all my connections on v-card & psu & MB etc. & all of them are good & hooked up right. I also checked the specs. on my PSU & it puts out 54 A on the 12v rail. Which should be more then enough to power the v-card I would think. I do have another PSU (my old one) to swap in, but it is only a 420 watt with only 18 A on the 12v rail. Do you think this would be enough to power up the v-card? (I purchased the new PSU just for the v-card upgrade).

skolpo : I tried uninstalling my old ATI drivers & booting up with the windows default display drivers & when I tried to install new drivers off the install cd I got an error saying no compatible drivers for my hardware, & wouldn't let me continue.

After messing with this thing for some time now, I was able to get it to boot to the desktop a couple of times where it actually didn't reboot itself for appx. 20-30 seconds after getting to the desktop, & when it did stay up that long windows gave me this error: "The system has recovered from a serious error" then it would reboot itself again.
I also tried different bios settings, different monitor, & even checked the temp. of the video card & it never got over 47C. So now I'm even more stumped by this. Maybe its a compatibility issue with the PCI-e 1.0 & 2.0 like Twoboxer suggested. If so, what would be a good choice for a new motherboard with my setup? Any ideas or help would be very much appreciated. Thanks in advance. JT2Fast4u...

Try the other psu - you don't have anything to lose except a bit of time. Just don't run 3D apps. If the system boots up and stays up, you know what you have to do. If it doesn't, we will not have proven anything.

The issue isn't the Rosewill's rated power - its whether your sample is actually capable of delivering it.

As I mentioned above, it really shouldn't be a compatability issue.

You could try installing the old vid card so you can boot up. Then uninstall all nvidia and ATI software. Then power down, install the new vid card, and try to boot up.

Twoboxer- I tried putting my original PSU back in (which is rated at 420watt/18A on the 12v rail) & my system does the same thing (reboots before, or right when the desktop comes up). I also tried putting my old v-card back in & uninstalled all my ATI software & drivers, then tried booting up, with the new v-card, & I still get the same results (rebooting). One thing I have found out is that whenever I take out the new card & put my old one back in, on the first boot-up, I will get two back-to-back errors saying "the system has recovered from a serious error". But I only get that the first time after switching the cards out. The next time I boot up or restart, I don't get that error (when I'm using the old v-card). So I would think this error, that I'm getting, is directly related to the new v-card. Wouldn't this be some kind of compatibility issue, or could it be a defective v-card? I would appreciate your thoughts on this one. Thanks again. JT2Fast4u

Try reinstalling your XP. Also, don't install the drivers from the CD. Use the latest drivers from the ATI site. They're a lot better and efficient. It does sound like a hardware problem from the GPU. Even if it's not getting full power from either PSUs, it should at least be able to boot up entirely to the desktop. Try RMAing the card if none of this works.

^1 Skolpo's got a good idea, but you can't get into Windows to do it. If your system is failing with two psus and two vid cards, the odds are small all of them are bad.

Which leaves us with mobo or drivers.

Can you get into Safe Mode? If so, uninstall all drivers and try to get into normal Windows.

If not, try booting from the Windows CD and do a repair install.

If you can't boot from the CD because it goes straight to Windows, get into BIOS and adjust the Boot Sequence so the Optical drive is first.

Let us know what happens.

Hi...Sorry about the delayed post but I just wanted to thank you guys, especially Skolpo & Twoboxer for helping me get my pc going again. I really appreciate it. Thank you!!! What I had to do to fix it was do a "repair install" of windows, using my old video card, then uninstalling all of my older display drivers & software then switched the video cards out for the final reboot & it worked. No more rebooting & I have ATI's 9.9 version drivers installed. Well thanks again. JT2Fast4u