Shoutbox

Check that the drivers for your IDE/SATA controller are installed correctly and are up to date. If that doesn't work:

Does the drive make funny noises (as if it's trying to read the disk but can't) when trying to access a CD? If it does, then try cleaning the lens with special lens cleaning materials and fluid. (Whatever you do, don't use your fingers [fingerprints] or a random cloth [dust, sharp materials could scratch the lens]). The lens has a different read pattern for DVDs than CDs so if only part of the lens is covered / dirty this may be the problem.

If it doesn't make funny noises, find a bootable CD and try to boot to it from the BIOS. If it doesn't boot, then the drive is likely screwed. If it does boot, then there's a driver / configuration error with your Windows install.