PC died, needs new graphic card but I'm so confused

Hi. I'm a new member who is mostly pc hardware illiterate. This is the first time that I've had to try to find hardware on my own since I've always had someone else to upgrade or repair my pc for me. I'll begin with describing the issue I had with my desktop pc 2 weeks ago.

One night I was watching a movie on the pc and it suddenly reboot itself without warning. When it tried to boot into windows it would just reboot over and over again. The only thing it allowed me to do was to get into the bios and I attempted to get into safe mode but no matter what the pc wouldn't boot into windows at all. I did manage to find out the error, it was unmountable_boot_volume. I had a friend to search the error online for me and he told me what it meant and there were several solutions, one being to use the winXP disc to repair windows, however I no longer had that disc. My sister made a copy of her XP disc for me since we have the save XP version and mailed it to me.

Before I could test the XP disc I had to reassemble my pc. The night it messed up I got the bright idea of taking the panels off the case to remove the RAM and harddrives. I was thinking that maybe one of the RAM sticks died or maybe the harddrive that the OS was installed on had died. Then 4 days later I bought a new laptop and connected my external harddrive to it so I could test out the main drive from my old pc. The drive worked just fine thankfully.

Now fast forward to yesterday, I got the XP disc in the mail. I reassembled the desktop pc and thoroughly checked if everything was connected properly. However the very moment I turned the pc on it let out this long, loud, ear piercing high pitched alarm sound & would not even show anything on the monitor screen. I was up until 2am this morning video chatting with my sisters boyfriend who was trying to help me make sure the pc hardware and cables were installed correctly. I tested the fans, RAM, harddrives, all wires/cables and everything seemed just fine. Then today I took the graphics card out, turned the pc on, and there was silence. The tower acted as if it was booting up normally. I put the graphics card back in, turned on the pc, and that same horrible sound appeared.

From what I gather, during that 2 week period of the pc sitting around (unplugged with no power source) somehow the graphics card died? I really have no idea what happened and how it happened but I was hoping that if I replace the graphics card that maybe the pc would then try to boot itself so I can put the XP disc in to attempt repairing the unmountable_boot_volume error.

So the main point of this post (sorry for the long story above) is about which graphics card to get for my pc. I've been looking online for hours and my brain is completely fried. I do some online gaming (which unfortunately makes my new laptop's fan go crazy). Even though I do gaming, I wouldn't really use the old pc for to much for that purpose. It would be more of a backup pc now but it would be nice to have a graphics card that could handle gaming.

I'm really not to sure what pc info I need to give. The motherboard is ASUS A7N8X-E Deluxe. Graphics card for it is Nvidia G-Force 6 Series (GeForce 6800 XT) 128MB. As this will be a back up pc I was hoping to only spend $30 or less for another card. I browsed eBay and Newegg.com but I'm scared of getting the wrong thing for the pc. If anyone can help me out I would greatly appreciate it.

Before you go racing off to buy a new card I think that you should check out your Power Supply. I think that there is a good chance that your original problem was caused by a failing PSU and this has lead to a fried Graphics Card. The PSU must be checked for stability and appropriate voltages before you try and run this machine in the future. Don't take the chance of blowing another GPU or other component.

How would I test the PSU? Also, I'm shamed to admit that I haven't cleaned the inside of the pc tower in around a year. There was quite a bit of dust built up inside the graphic cards fan. This probably helped lead to its demise.

Thanks for the suggestion. I had hoped to stay in the range of $30 or less, if that's even possible, due to my budget being very tight a the moment now that I had to buy the new laptop. I did a lot of googling for info on the motherboard and graphics card but everything just confused me and I wasn't sure what card would be best for the motherboard and was afraid that if I got one then it wouldn't be compatible. I always have the worst of luck when choosing items like that.

On a side note, if your laptop fans need cooling help there a a number of cooling pads that will help. You can browse them at New Egg and other sites at Appx 25.00 I have a cheap two fan Targus that also gives me 4 usb hook ups also.