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Changing Active Partition Can Make Your System Unbootable
Article ID: 228004 - View products that this article applies to.
This article was previously published under Q228004
NoticeThis article applies to Windows 2000. Support for Windows 2000 ends on July 13, 2010. The Windows 2000 End-of-Support Solution Center
(http://support.microsoft.com/?scid=http%3a%2f%2fsupport.microsoft.com%2fwin2000)is a starting point for planning your migration strategy from Windows 2000. For more information see the Microsoft Support Lifecycle Policy
When you use the Windows Disk Management snap-in tool to mark your primary partition as active, the computer may not start up if the partition marked as active does not contain the Windows boot files (or boot files for another operating system).
NOTE: When this happens, you may receive the error message when you try to start the computer:
NTLDR is missing
This problem occurs because on Intel-based computers, the system partition must be a primary partition that has been marked as active for startup purposes. This partition must be located on the disk that the computer gains access to when starting up the computer. There can be only one active system partition at a time. If you want to use another operating system, you must first mark its system partition as active before restarting the computer.
To resolve this problem, perform one of the following: