I installed a new video card on my pc and now it shuts down randomly

Hello,

This is my very first time installing a video card onto a motherboard and as a result, need help on what I am doin' wrong

I have recently bought an Axle3d Nvidia Geforce 9500GT and have inserted it into the PCI-E slot. The power supply is a 450W and the motherboard I have is a P965T-A with what I believe is a 2.4 GHZ(not sure if that is the original speed or the overclocked speed) Initial Duo Core processor.

The problem I have with the computer is that after I inserted the 9500GT into the pc and installed the graphics driver that came with the card, the computer now shuts off expectedly; It shuts down right after I turn the PC on, durin the xp logo screen, and up to several minutes into the windows desktop.
I also notice that when I hit restart, the computer jsut shuts off.

The problem happened when I installed the driver the first time and rebooted. After several attempts to boot the pc, the computer was still on when I got to the desktop, which installed the video card driver a second time (it didn't seemed that the driver installed the first time.) Not sure if this was the problem, but both installation times, it said that the driver I had on my pc was more updated than the one on the cd. Also, the 2nd installiation(first time, it installed really quick so I doubt it installed the first time,) it asked me to replace the nv4 files. I said no on the first one (nv4 display It hink), but yes on the dll one. Lastly, durin these at the end of the two installiation, I would get a registry overwrite persmission on two files. I can't remember one of the files (something like foxy or voxy or something?), but the one I can remember was nvcpl.dll

I am not sure what to do. My father is being stubborn and won't help, and instead would shrug me off claiming that I permenantly broke the pc with a wrong graphics driver (which is a lie since the computer still boots and he didn't check what is wrong with the pc) despite he was the one who custom built my PC as long as I can remember. So please, if anybody can help, reply.

Are there an easier way to remove all traces of the video card driver other than going to add/remove hardware driver on winxp?

Connectin the power cable from the psu to the motherboard, right? If so, it is connected. However, if you mean I have to connect the power cable from the psu somewhere on the graphics board, then no. I don't see any plug on the board to plug anythin' extra other than the stuff on the side. Sorry but this is my first time upgradin my pc, so I may say something dumb.

Reset your cpu back to it default rating until you get your video card installed. Get the latest drivers from your video cards web site.
You may also need to upgrade your power supply depending on how many devices you have running. This includes Usb devices

http://extreme.outervision.com/psucalculatorlite.jsp
To find out if you need A PSU upgrade set TDP, cap aging, and Sys load all the way up. If thats ok then get a friend to help.

That should not cause It to shut down tho. Just be really slow my avg use is about 1gb running vista 64 ultimate with my startup processes (about 45) Hope that helps