Yeah it sounds like your Master Boot Record (MBR) is shot. The data might still be there, but windows doesn't "see" the drive. I agree with Lasereth as booting to a live CD of linux will work. Ubuntu's newest liveCD would be great for that. I've had the same problem myself and used a liveCD to access the information with no problems.
Ubuntu Home Page | Ubuntu
Has download instuctions for burning a bootable CD. Should be able to boot the PC via CD and drag and drop files onto a flash drive or extrenal hard drive.