Using the Recovery Console, copy the Ntldr file from the Windows XP CD-ROM to the root directory of the current active partition. On Intel x86 computers, this is always drive 0, the drive that the system BIOS searches when the operating system starts. On Intel x86-based computers, the system partition must be a primary partition that is marked active. The system partition refers to the disk volume that contains the files that are needed to start Windows (for example, Ntldr, Boot.ini, and ).

If the partition that has been incorrectly marked as active is formatted in the FAT file system, the FAT32 file system, or the NTFS file system, you may be able to use the Windows Recovery Console to correct the behavior.įor more information, see What are the system recovery options in Windows?. For more information, see Create a system repair disc.

Remove the boot floppy disk, and then restart the computer.īoot the computer by using a Windows XP boot disk.

Click Set active partition, press the number of the partition that you want to make active, and then press ENTER.

When you are prompted to enable large disk support, click Yes.

At the command prompt, type fdisk, and then press ENTER.

Boot to a command prompt by using a Microsoft Windows 95, Microsoft Windows 98, or Microsoft Windows Millennium Edition (Me) boot floppy disk.

Try changing the active partition by booting to a floppy disk and then using disk utilities to manually change the active partition: To resolve this behavior, use one of the following procedures:

Resolutionīefore performing the steps listed below, make sure that you have a good backup of your critical data files.

If you want to use another operating system, you must first mark its system partition as active before restarting the computer. There can be only one active system partition at a time. This partition must be located on the disk that the computer gains access to at startup. On Intel-based computers, the system partition must be a primary partition that has been marked as active for startup purposes. This behavior occurs if the partition marked as active does not contain the Windows boot files or the boot files for another operating system. This article provides a solution to an issue where the computer doesn't start after you mark your primary partition as active.Īpplies to: Windows Server 2012 R2 Original KB number: 315261 SymptomsĪfter you use the Windows Disk Management snap-in tool to mark your primary partition as active, the computer may not start, and you may receive the following error message:

Make windows partition bootable