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How to restore the system/boot drive letter in Windows
Article ID: 223188 - View products that this article applies to.
This article was previously published under Q223188
Warning Do not use the procedure that is described in this article to change a drive on a computer where the drive letter has not changed. If you do so, you may not be able to start your operating system. Follow the procedure that is described in this article only to recover from a drive letter change, not to change an existing computer drive to something else. Back up your registry keys before you make this change.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
249321This article describes how to change the system or boot drive letter in Windows. For the most part, this is not recommended, especially if the drive letter is the same as when Windows was installed. The only time that you may want to do this is when the drive letters get changed without any user intervention. This may happen when you break a mirror volume or there is a drive configuration change. This should be a rare occurrence and you should change the drive letters back to match the initial installation.
(http://support.microsoft.com/kb/249321/ )Unable to log on if the boot partition drive letter has changed
To change or swap drive letters on volumes that cannot otherwise be changed using the Disk Management snap-in, use the following steps.
Note In these steps, drive D refers to the (wrong) drive letter assigned to a volume, and drive C refers to the (new) drive letter you want to change to, or to assign to the volume.
This procedure swaps drive letters for drives C and D. If you do not need to swap drive letters, simply name the \DosDevice\letter: value to any new drive letter not in use.
(http://support.microsoft.com/kb/322756/ )How to back up and restore the registry in Windows
Article ID: 223188 - Last Review: September 11, 2011 - Revision: 7.0