Microsoft KB Archive/315943

= You Cannot Access an EFI System Partition with the Mountvol Utility in a WinPE Environment =

Article ID: 315943

Article Last Modified on 12/1/2007

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APPLIES TO


 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, 64-Bit Datacenter Edition
 * Microsoft Windows XP Professional x64 Edition

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This article was previously published under Q315943



SYMPTOMS
If you use the Mountvol utility (Mountvol.exe) in a Windows Preinstall Environment (WinPE) on either a Windows XP-based or Windows Server 2003-based computer, you cannot gain access to the Extensible Firmware Interface (EFI) system partition by using the mountvol /s command. For example, if you try to use the mountvol x: /s command, you may receive the following error message:

The system cannot find the file specified.



CAUSE
This behavior occurs because the Mountvol utility is not supported in WinPE environments.



RESOLUTION
To work around this behavior, use the Diskpart utility (Dispart.exe) instead of the Mountvol tool. To use the Diskpart utility:
 * 1) Click Start, click Run, type diskpart in the Open box, and then click OK.
 * 2) When the Diskpart utility starts, type select disk  at the prompt (where   is number for the mapped ESP disk), and then press ENTER.
 * 3) Type select partition  at the prompt (where   is number for the mapped ESP partition), and then press ENTER.
 * 4) Type assign letter= at the prompt (where   is the drive letter that you want to assign), and then press ENTER.

After you follow these steps, you can access an EFI system partition by using the drive letter that you assign to the partition with the Diskpart utility.



STATUS
This behavior is by design.

