|Try each step one at a time, restarting your computer to test each time. If one step does not work, continue to the next step until the error message does not appear again.|
Remove any disks from CD-ROM drives.
Unplug any external USB flash drives.
Unplug any external hard disks.
Disconnect any recently added hard disks and restart your computer using the original hard disk. (Skip this step if changes have not been made to the computer hardware.)
Check all cable connections to your hard disks. Verify that your hard disk is being registered by the BIOS.
Check the boot order in the BIOS. Make sure that the BIOS is attempting to boot from the correct hard disk. SATA hard disks normally boot before IDE hard disks, so you may have to install your operating system onto the SATA hard disk if you have recently added a SATA disk to an IDE-only system. Instruct the BIOS to boot from your preferred hard disk first. If the computer refuses to boot from your preferred hard disk (for example from an IDE hard disk because you have installed a SATA hard disk), install a boot manager to the first hard disk and configure it to boot from the hard drive of your choice.
Verify that the SATA disk containing the operating system is on the first SATA channel.
Inspect your hard disk for errors. If your hard disk is failing, replace it and reinstall your operating system. If your hard disk is corrupted, attempt a repair. If a repair is unsuccessful, you may need to reinstall your operating system.