cd/DVD-rom cant read/verifying..DMI Pool data error loading operating system

[swordfishwan]

The dvd rom drive does not read but the light keeps flashing as is its busy and the pc freezes..@ my computer no icons are visible until i eject thats when it stops freezing. i've checked with device manager but it seems to show that the drive is working...i've also unmounted the image for need for speed most wanted which i thought might have been the problem but to no avail.
so i tried to restart the machine (after trying everything..it always comes down to pulling the plug from the mains) now it says verifying pool data.... error loading operating system..
the boot sequence is in this order (harddisk, floppy,cd-rom) but nothing happens..
the usb ports still works..if that helps anything..