A disk read error is a sign of a problem with the hard drive. Boot the machine and as soon as you see the mfg logo, start pressing F8 repeatedly. This should get you the advanced boot menu. Choose Safe Mode Command Prompt. When you get to a command prompt type CHKDSK C: /F <enter>
It will tell you that it can't perform the fix funtion because the drive is locked and ask if you want it to run the next time it boots. Say yes and reboot.
If you get the disk read error just powering on, then it looks like your drive has failed.