When I started up my computer today I found that it will not boot. The startup runs until the part where the Windows logo should come up. When it gets to this point the
screen either turns black, states a disk read error and asks me to reboot, or SHOWS a black screen with a white blinking cursor at the top left corner.
While starting up it does show the Gateway screen and will let me enter BIOS. I reset BIOS to defualt system settings, but this did nothing to help.

Previously, actually yesterday from the time of this post, I installed a new video card. The video card that I had previously installed was a NVIDIA GeForce 6600. This
card was installed in the AGP slot on my computer. The new card I bought, a NVIDIA GeForce 8400, fit into my vacant PCI slot. I put in the 8400 and removed the 6600.
For some reason it wouldn't boot this way, so I put back in the 6600 while keeping the 8400 in at the same time and the computer started up. It worked all last night, but I think installing this new card is causing the problem that I'm having now. Currently both cards are still in the computer.

For now, since the computer won't really START, I can't give you any specifics about my system specs, but I can tell you what I remember.

System Manufacturer: Gateway
Operating System: Windows XP Professional SP3
Processor: Intel Pentium 4
Direct X: 9.0 c
Video Cards: NVIDIA GeForce 6600(AGP) & NVIDIA GeForce 8400(PCI)
RAM: 1GBNevermind it started up today when I got home from school.
Seeing as right now I'm on the once problem computer, I think it's safe to say that my solution worked.

For those who might have the same problem, make sure you don't have any kind of DISC in your CD-ROM/DVD-ROM drive.
For me this has never caused problems before, but when I took my COPY of Fallout 3 out of my disc drive the computer booted normally.
As to why now my computer won't boot with a CD in the drive and why it WOULD before...I do not know...

All I really know, and care about, at this point is that my computer works.