Non System Disk or Disk Error

The error message is caused by the Basic Input Output System (aka. BIOS) of your computer when the Master Boot Record (MBR) of the primary partition of your hard disk is missing or corrupted. The same problem can happen also, due to the boot drive improperly being configured in the BIOS. In situations like these, the stored data on the disk partition may remain undamaged (if you are lucky) but you can't access them.

You need to repair the MBR to fix this problem. The Mechanic can construct a new MBR for you.