First, I got a BSOD that initiated the problem. After I restarted my computer, I got a message that said Disk Boot Failure, Insert System Disk and Press Enter. I put in the system disc in the disc drive and pressed enter.
The keyboard was not working so I changed the BIOS so that the first priority was the disk drive and all the other priorities were disabled so I could run the system disk.
The same problem occurred(It said Disk Boot Failure, Insert System Disk and Press Enter) and then I removed the hard drive to test the computer. Once I removed the hard drive, the system disk ran like normal and took me to the Windows Vista Installation Menu. Once I reconnected the hard drive, the problem reoccurred.
The keyboard doesn't properly respond in anywhere other than the motherboard starting screen and the BIOS. The keyboard didn't even work when I went to the boot menu.
Windows Vista Home Premium x64
500 GB WD Caviar Blue
4X1GB DDR2 1066Hz
Nvidia Geforce GT 430
The System Disk request is appearing because your HDD has failed most likely. The reason why it will boot up to the installation menu is because when you unplug the HDD the BIOS detects the bootable DVD in your DVD Drive. When you plug the HDD in your BIOS is set to boot off that first and when it fails to do so the system halts. It then asks for a System Disk. What that means is the BIOS is seeking out a boot able disk. This could be a boot able DVD or CD or HDD or in some cases a USB stick. That is why the System Disk request is worded in a generic fashion.
I think your HDD may be dead. If it is then you will need to replace it and do a fresh install. If you have back ups you will need to recover your data from there.