any luck on installing video card in HP Pavillions?

Have you disabled onboard graphics? That could cause reboots.

Yes, I changed the BIOS to use the PCI-E vice onboard graphics.

Most of the time the machine booted up fine but as I tried to install drivers the machine would re-boot. The first card just re-booted continuoously without getting to the driver install but all (4 cards 2-each) did basicly the same thing, would re-boot the computer randomnly after ebing on just a minute or 2 and even just go into a constant re-booting cycle...
I really think it is a PSU problem but there must be some card someone has been successful with..

Did you unistall the old drivers? You can do this under device manager. After you did that did you use drivercleaner to make sure everything is gone?

As to the power supply, I doubt it. I use to have an HP a700n with a 250 watt powersupply running an x800xl, so what im saying is that for short term stability its probably not the problem. Did you do the following?

1. Remove old drivers
2. Use drivercleaner
3. Shut down
4. Install new card
5. Set changes in BIOS
6. Install new drivers
7. There is no 7

Hope that helps

That's really pushing your luck. I don't trust the HP PSU with my new A64 and DFI board, so I'm getting a new Thermaltake one.

Well, I bought and installed an ATI X700 and still had the same problem sooo... I bought and installed a 450 watt 2 rail Antec power supply and...Same problem. The system recognizes the card and all that rot. Windows boots normally, no errors. Already had ATI drivers installed and it picked up on the new card just fine.

Now after about 3 minutes the computer will stop sending video to the monitor (it goes to sleep) and the computer will reboot. It does not matter wether I am using the computer or it is just sitting there looking dumb.
Randomly it will just lock up, if it did not re-boot itself  The fans are still running (case/CPU/PSU) but the hard drive light will be lit up steady but I hear no HDD noise (it is spinning at idle vice "working" on something)

Once I remove the video card everything works fine.

I can only assume a bad PCIe slot on the MOBOARD or some compatability issue on the MB. So I am off to get another MB and see how it goes.....

Yeah, and good luck to the guy trying to get a new mobo for an HP

Well I went out and got an ASUS board and stuck it in. It had integrated graphics (only micro ATX I could get) and after transfering everything over except for a different HDD, I hit the ON button and lo and behold! The graphics were all screwed up and I couldn't read the post or CMOS stuff. Well installed the x700 and got graphics I could read most of the time but it would lock up after a few seconds.

In the end I put everything back together as original HP stuff and am now using it, I suppose I will settle for what I have...

After 4 different video cards, a new PSU, and a new mother board I still can't get a decent video card on this computer.....LOL! While changing out the video card I broke the little tab thang on the PCIe connection so I'm sure HP will not honor a MoBoard under warranty either...lol.

Bad luck, but at least you can say that you tried absolutely everything

Well I used to build PCs for myself. First was a Cyrix DX 40. But after many many builds it got to be too frustrating trying to figure out just exactly which POS is at fault. So I thought I could just pick up something and upgrade as I went.......so much for that!

Should have ordered a custom build and went from there....

You didnt do yourself any favors by installing a new motherboard on an existing version of windows. That can create all kinds of problems. Im actually surprised it booted windows at all since the windows xp that HP gives you will generally only boot if it recognizes an HP registered board. They tattoo the damn things so you cant do exactly what you just did.

I didnt read anywhere that you actually removed the old drivers, so did you do that or no? And hp has a pretty good support center, ive used it myself when i had compatability problems, did you try that?

I used a separate hard drive and had a copy of XP PRO ready to install on it, but I couldn't get into the bios at all. The computer kept freezing at before entering the bios setup or I could not read the stuff on the monitor. It was like the vertical sync was way out, just a bunch of hashed lines. That was with the IGP but with the X700 installed I could read the boot screen but it locked up there.

I took it down to just one stick of ram, no USB hooked up and still had the same prob. It did no better with the HD or jsut a DVD player or any combonation I could think of...

TO frustrated to mess with it. At least it works when put back to stock...

I did not remove the drivers when I put in the X700( ATI drivers already installed for the integrated X200), I did when I tried the 6600 cards. As soon as window booted up it recognized the X700 and all that but would freeze/re-boot just like it did with the other cards, so I was sure it was a PSU issue and that started the whole mess with the PSU and Motherboard install (to no avail)

It is a HP 19 inch LCD, wonder if it is a problem in some strange way?

I've got an HP pavillion, though a different model, and they give special drivers for it, not available through ATI. Are you using Catalyst 6.4? Did you get it from ATI or HP? HP's drivers are different, so you'll probably need to install new ati drivers.

I've just removed the old video drivers and tried installing the X700 again. No go.

Something else that makes me think it is hardware. When I start the computer, normal configuration, the case and CPU fans start on fast then slow down after 1-2 seconds. When a new card is installed the fans start at slow (very slow) speed and stay that way. Kinda thought the PSU because of that and figured when it was doing it's boot check of DVD drives it just took to much juice and caused it to reboot all the time.

But I'm stumped and a bit fed up with it all.

Using ATI drivers and even updated the Microsoft Frame network stuff...

Well, sorry that didn't help.   I can't think of anything else to try, either.

Thanks for the input, I really appreciated it. Thanks again