Hi, I have received computer parts and I started to experiment with 3 computers I picked up for dirt cheap. I already screwed up two of them by installing a video card (trying to get dual monitors) and both computers give me a black screen on boot up and restarts itself endlessly.

Even if the card fits the slot perfectly, I'm assuming that some video cards won't work with some motherboards and cause them this problem. Now even without the card installed in both computers they will keep restarting once the windows 7 logo shows up. I tried formatting the hard drive, and I even had a couple spare hard drives from the parts given to me and it's doing the same thing, it's like the CMOS kept the info and keeps looping.

So now that I've screwed up two boards, I have one left and Id like to get it to work. It's WORKING fine right now, it has a single onboard VGA, but I have two monitors sitting on my desk and Id love to get this computer to use both monitors..

The computer is a Dell INSPIRON 545 I believe, from searching online the motherboard is a DELL DG33M06

The video card I have (looks older): WinFast PX7600GT

Any help on this would be appreciatedOS Boot Loop is usually caused by mismatched hardware to that of the original build. Are you trying to get a copy of Windows from one computer to work on ANOTHER, such as of the 3 systems if you take the hard drive from one of them with the OS on it and move it to another computer with better hardware specs to make the best computer from all 3 systems parts, you can run into this issue.

Solution is to perform a full clean installation of the OS so that it can pair up the hardware to the OS for drivers and all.

Video Card installation can damage a system if installed wrong, video card is defective and shorts or redirects higher voltages like 12 volts to a lower voltage pin and smoke the motherboard etc.

I'd focus on getting systems to run correctly in integrated video first and then introduce the video card later after you know that the base build of the system is healthy and your ready to move on to better video card.Thanks for your reply, I tried installing the video card with my third computer and the same thing happened. It will boot into windows 7 for id say 2-3 mins. Then I get a windows error and it restarts itself into that loop.

I followed your advice, I went back to the original hardware, and it seems to be working fine now. It was late last night so I only had the PC on for 10mins or so.

I was reading online that perhaps disabling the onboard video in BIOS could fix the windows error. I'm really trying to get the dual monitor going.

I'm still new at working with computers, but I have a general idea, read online and everything seems to pass with the older video card to fit into the motherboard. Like I mentioned above it will work for a couple minutes into windows before I get the glitch.

I do have a 400W power supply, and looking at the specs of the video card it suggests a 300W power supply. Does it actually take 300W of power?? or they recommend 300W with the rest of the build?

Good news is your suggestion about going back to the original hardware and then formatting drives from scratch may save my other two computers.. Ill let you know when I get a chance to work on themDepending on the condition of the power supply it may be weak even though rated 400 watts. Additionally depending on the age of the power supply it might have bad swollen or leaking capacitors. What is the brand name on the power supplies you have as well as for some brands 'false advertise" actually wattage to be greater than what they truly can maintain.

Leaning on power supply issue with additional info suggesting it runs windows fine for a short while and then you get the crash and boot loop which is common with a weak power supply.

However it could also be the cause of a video card that overheats. If the video cards GPU overheats it will cause a hardware crash and bot loop as its cooking, so make sure fan(s) are spinning on video card and not caked with dust etc. If its a passive heatsink video card without a fan, TRY adding airflow in front of the video card such as a SMALL fan or box fan to blow air into the case to keep the passive heatsink from building up a hot spot and see if that makes it behave.