Having trouble upgrading a video card

I have known for awhile that my video card was dying. The fan quit
months ago, and the motherboard would beep if I watched a video or
scrolled a lot. For the last month or so, the computer started
crashing, and would take multiple tries to boot up. Then it died
completely. The computer would "run", make a few normal clicks and
beeps, but nothing ever came up on the screen.

So, I got a new (used) video card. It goes into a slot and hooks up to
two power plugs for hard drives. I have 3 hard drives, so I unplugged
one to allow two plugs on the same line to go to the video card. The
computer came on with text on the screen, so it was an instant
improvement, but I disabled the wrong hard drive. It couldn't boot.
So, I hooked that one up and took off a different one. Results were
not great. I forgot which plug went where. So, i redid it, and it
booted up, but had a new error.

I wrote down the name of the missing file, but I have misplaced the
paper. I put in the windows CD to repair it, and it didn't want to
repair. So, I picked the overall reinstall. It went through that
process twice. Not successful the first time. The computer started
beeping a lot when I tried to reboot. The second time, it came up in
safe mode.

The current error message is this:

During the last boot-up, your system hung for an improper CPU speed.
Your system is now working in safe mode. To optimize the system
performance and reliability, make sure the CPU speed conforms with the
specifications or your CPU.

Would changing a video card affect the CPU speed? It says the CPU
speedis 2667MHz which sounds correct.

My computer is a system that was purchased and put together by
somebody else. I bought it used, but he did give me all the CDs and
booklets that came with it. The motherboard is Asus brand, P4PE. I
have had it for 3 or 4 years with no other problems.

The new video card is nVidia eGeForce 6800 Ultra (256MB). The old one
was an Asus V9180 Suite 64Mb DDR MX440


Any suggestions on what I should try? Should I go ahead and leave the
settings the same and try to reboot it again. Or should I try
something different?

According to the box, I have all the minimum requirements for this
video card. The minimum CPU is 2 GHz.