If you ever get "MBR corrupt" or Error loading operating system" error messages on your computer, it is telling you that BIOS cannot locate the Master Boot Record on the first sector (the boot sector) of your hard drive. This is when you will have to restore MBR. The MBR tells BIOS which partition on the hard drive contains your operating system and then loads it into memory from there. With a damaged or corrupt MBR, BIOS cannot locate and start the operating system. To restore MBR you need to enter Recovery Console in Windows XP, you will need to boot from the Windows XP CD. 1. Insert your Windows XP CD into the CD tray and restart your computer. 2. Watch the screen for a Press any key to boot from CD. 3. Press a key to start the computer booting from the Windows CD. If this is not done, your computer will continue to boot to Windows XP. If this happens, reboot and try to boot to the Windows XP CD again. Windows XP will now preload a number of files in preparation for either a reinstallation of Windows XP or for use of the Recovery Console. * Do not press a function key if asked to do so during this process. This is only necessary when installing Windows XP or reinstalling Windows XP. 4. When the Windows XP Professional/Home Setup screen appears, press R to enter Recovery Console. 5. The Recovery Console is now loading but needs to know which Windows installation to access. Unless you are running more than one version of Windows XP, then on the which Windows installation would you like to log onto question, press 1 and then Enter 6. To the Type the Administrator password request, enter the password and press Enter. * If you do not have a password or Windows XP normally starts without asking for one, simply press Enter.  The Recovery Console is now fully loaded and the cursor should be sitting at the prompt. 7. To restore mbr, type "fixmbr" without quotations and then press Enter. The fixmbr utility will write a master boot record to the hard drive that you're currently using to boot into Windows XP. This will repair any corruption or damage that the master boot record may have.   8. Take out the Windows XP CD, type exit and then press Enter to restart your PC.  Assuming that a corrupt master boot record was your only issue, Windows XP should now start normally. Windows Vista and Windows 7 have built in versions not requiring an installation CD to restore MBR. Restore MBR by PC Apprentice 2009 - 2017 I sit looking at this damn computer screen all day long, day in and day out, week after week, and think: Man, if I could just find the 'on' switch... - Zachary Good Click Image to Enlarge Click Image to Enlarge