Error message when I openmy computer:

-Take a look in your BIOS console to see if your primary boot device is connected and shown in the list.

-if yes then, bootsector on primary boot device is missing, and you might have to connect this HDD to a different computer and back your data up, and then connect it back to your computer and run the windows recovery. make sure you scan for bad sectors after your system is up and running.

-if no, then shut your computer off and groud yourself and take all the precautions for static and open the cabinet and make sure that your primary boot disk is securely connected to the motherboard and power connector is firmly connected to it (you can try switching the cables to see if its an issue with the cables, motherboard ports or power supply)

hope this helps you to pin point the issue..

Please make sure that you have set your computer to boot from your HDD initially. You can do this by pressing F5 or F8 button upon restarting the computer thereby going to the CMOS settings, then check the boot sequence. Your HDD must come first. You may press PgUp or PgDwn to change the boot sequence.

If your boot sequence is OK and you have Windows installed in your computer, it sounds more like the Master Boot record of your HDD is screwed up. Boot up with the Windows cd into Recovery Console and see if you can access the C:\Windows directory (or any other directory you know on that HDD). There are also utilities on the internet that can scan your HDD for any problems, physical or software faults, and may try to correct them (be careful using this - it may delete stuff).

Easiest way is to download a Live OS CD like Knoppix or Ubuntu Live that has support for NTFS filesystem and using that to access the HDD directly. That will tell you if you have a problem with your HDD or not.

If you have tried all the above steps and you still have the same error, you may reinstall OS if you still have your original Windows CD.