Add, Remove or Change Windows Drive Letters
With Microsoft's Disk Management Tool.
Within a few limits we can change and arrange Windows drive letters to our own
preference, allowing us to maintain consistency across various Windows installs.
What you can't do. You won’t be allowed in Disk Management to change Window’s own drive letter and this is indeed something you should not attempt by any means. You may also have another drive with a letter you can't change or remove and this may be a Windows System partition. In pre-Win7 versions of Disk Management it took a workaround to alter a System partition drive letter, but from Win-7 it is possible unless some important component such as a paging file has been placed on the drive.
Dependencies. On well used Windows systems or factory configured machines it would be prudent to be cautious in changing a drive letter because Windows or a software application may have a dependency to some component that will no longer be available if the path to its drive has been removed. Returning a letter to what it was is likely to restore any required links, but we would still advise that removing or changing drive letters is something that is best only done during the early stages of configuring a new system.
For a primer and details on how to start the Disk Management tool please refer to the first article in this series.
If you get the first of these two boxes it means the operation cannot be carried out and so must be cancelled. If the reason for this is because the partition is the boot volume in Win7/8, or the boot or system volume in previous Windows versions, then there are no other options. If however it is just a paging file that is causing the block then this could be moved to another partition before trying again.
The second warning box shown in fig:4 is what you will receive when removing the letter from a system partition, or if there is some other software component that is currently in use on the drive. Generally speaking if it is some Windows service it will rarely cause an issue as Windows can and will adapt. If it is some software application that you have installed then there is a fair chance that you might have a problem with it. If you do then the options would be to reinstate the drive letter, or try to identify and relocate the offending components, or try removing the app and reinstalling it after drive letter changes.
To add a letter to a partition or drive that currently has no letter attached to it then proceed as before to the step shown in fig:2. This time the list window will in typical circumstances be empty and the Add button will be the only available choice. Clicking it will give you the familiar options dialog where you can select a letter from the drop-down box. Once selected and you’ve clicked the OK button the operation will be immediately performed.
Mount in a Folder.
When you are adding a drive letter there will also be the option to mount to a folder, but we do not recommend this for multiboot machines or where you are cloning or moving operating systems around. We advocate keeping things as simple as possible as it can be easy to lose track and control of volumes and data if they are not all kept in the one place with distinct and fixed labels. For experts only. See here for a little bit more and some links.
No Drive Letter.
Remember that Disk Management will only work with partitions that are fully Windows supported. If a partition is of a non-Windows file system, or has been modified in certain ways perhaps by backup software or a manufacturer’s recovery system, or it has been hidden by a bootmanager, then it won’t be possible to give it a drive letter.