Subscriber Larry wrote in response to a comment in one of my other articles:
How do you assign drive letters with Windows features?
Why might you want to change the drive letters assigned by Windows?
One time might be if you add several drives from an older computer. Windows will normally assign the first hard drive as C: (and install Windows there) and assign the CD/DVD drive to D:.
Actually, the CD/DVD drive will be assigned to the first available drive letter after the hard drive partitions have been assigned. Since Microsoft recommends that the physical drive be partitioned as one large drive, the hard drive is normally C: and the CD/DVD is normally D:. But, you can change that…
Also, be aware that Windows sets its Drive Letters for individual partitions — a hard drive can contain multiple partitions, each recognized by Windows as a different "drive."
Let’s assume you added two drives from an older computer. You are probably used to some of the files being on E: and others on F: — but Windows set their drive letters as F: and E:. You’d like to get the drive letters assigned in the old pattern.
The process is pretty easy, although seldom needed. Using this method, in earlier versions of Windows, you can change drives other than the Windows boot drive (normally the C: drive).
Windows 7 appears to allow you to change the C: drive — but a warning here — changing the drive letter for the drive that stores Windows and your programs should be expected to break things. Do it at your own risk!
In order to easily change the drive letter assignments, you can use the Disk Management Console (diskmgmt.msc). You can open it easily by clicking on the Start Button (Windows Orb). Then typing diskmgmt.msc in the search box to locate it, and double-click on diskmgmt.exe.
To change the drive letter, right-click on the drive to be changed (it will highlight and an option list will open). Then select the option "Change Drive letter and Paths…".
If you have multiple drives and want to swap their letters, you will need to do a three-step shuffle.
Say that you have two hard drive drives E: and F: and you want to reverse their order.
You can’t swap the drive letters directly, but the fix is almost that easy. Change E: to an unused letter like R:, then change F: to E:, and finally change R: to F:.