Restore your Windows XP Master Boot Record (MBR)

• Boot your computer with your Windows XP CD
• Choose to "repair a Windows XP installation using Recovery Console"
• Select the windows installation to repair. There should really only be one unless you have more than one instance of windows on your computer. You will be prompted for the Administrator's password. If your Windows XP is Home edition and you don't know what the Administrator's password is, try pressing "Enter"
• Use the fixmbr command and answer yes after the warning:

C:\WINDOWS\> fixmbr

• Now reboot

C:\WINDOWS\> exit

• That's it! Reboot your computer and it should automatically start Windows XP.

Troubleshooting

• You may run into some more issues if your active partition was incorrect or was set to a partition that was not windows. When this happens you will get the error:

NTLDR is missing.

Press Ctrl+Alt+Del to restart.

• In order to fix this, you actually need to obtain a Windows 95, 98, ME boot floppy or CD. If you can't obtain one, you can also make your own boot disk at http://www.bootdisk.com/. Make sure the one you choose has the fdisk utility.
• Use the boot disk to boot to a command prompt.
• Run the utility: fdisk
• When you are prompted to enable large disk support, click Yes.
• Select "Set active partition." Press the number of the partition that has Windows XP installed, and then press ENTER.
• Press ESC.
• Remove the boot disk, and then restart the computer.

References

• http://support.microsoft.com/?kbid=315261
• http://www.webspinnerstudios.com/how-to/system/windows/active_partition_changed.htm

-- JesseSuen - 05 Mar 2006