Changing Drive Letters in Windows XP or Windows Vista

This discussion gets a little wordy, so don't let that intimidate you, the process for changing drive letters is relatively simple and I have just attempted to explain some scenarios which may cause drive letter swapping.

If you're using an external hard drive to do backups or drive images, once in a while I end up with a customer who had problems with the computer deciding, on it's own, to change the drive letter when the computer boots up.  This most commonly happens when the computer has multiple CD/DVD drives and/or memory card readers.  It is simple to fix this problem, so print out and follow the procedure here to change the drive letter to stay the same as it's designated in the backup program.  Also, if you have two external drives and you switch them from another location, you may have a problem if you plug them both into the computer at the same time.  Let's say you bought an extra drive and want to copy the files from the existing drive the first time you use it.  If one drive is F and the other G, the next time you plug in the drive which was labeled G will again be drive G even if the other drive is not plugged in.  Since your drive backup or imaging program is looking for drive F, it won't work, so follow the procedure discussed here to correct the drive letter.

First of all, to keep things simple for the sake of this procedure, let's assume that the computer has one hard drive, and two DVD drives.  If your computer has memory readers, etc., the only difference is you will have more drive letters to fuss with, but the procedure is the same.  Anyway, in this case, the hard drive in the computer will always be C.  If the computer has the software installation programs on the hard drive, they are on a partition which will be drive D.  The first DVD will be E and the second F.  That means when you plug the external drive into the USB port it will be drive G.  For the sake of this discussion, let's assume that one day you boot the computer up and the external hard drive all of a sudden has changed to drive E.  You now go through this procedure to prevent this happening again.

Both versions of Windows have a simple utility to change drive letters.  One thing to keep in mind is that in order to change any drive's letter, you can't have two drives using the same letter, so you will have to change all of them (after the hard drive letters) in order to get the results you want.

So, in this scenario, go to Start, Control Panel (if you have Windows set to the old style start menu, you will go to Settings, then Control Panel), then make sure to click on Classic View on the left pane.  Double click on Administrative Tools.

Now, double click on Computer Management.

NOTE BEFORE YOU START THIS:  When you change the drive letter of any drive, the computer will want to reboot to make the change effective.  DO NOT waste all your time rebooting after each change, wait until you have changed all the drives before rebooting the computer. 

In the left pane click on Disk Management, give the computer time to refresh the view, then in the right pane, scroll down the external hard drive, then right click with the cursor over the drive designation.  You will get a pop up menu.  Now, select Change Drive Letter and Paths . . ..  

This is where the computer will not allow you to have two drives with the same letter, so since, in this scenario, the external hard drive changed to E and you want it to be G, the first thing you need to do is go to Drive F, then change it's drive letter to H.  Now go to drive G and change it to drive I.  This will allow you to change the drive letter of the external hard drive which is listed as drive E to drive G.  Now, change drive H back to E and drive I back to drive F.  Now you can shut down and reboot the computer, then you won't have this problem again.