Sometimes when you install new hardware or remore a hard drive, the drive letters can get out of sync. For example, if you added a new hard drive on a system with an existing hard disk (C) and DVD drive (D) then the new hard drive letter would be E. If you wanted to change this letter to D and make the DVD drive E (swapping them) then you should follow the instructions in this guide.
原帖地å€: TechSpott - Computer and technology forums http://www.techspott.com//showthread.php?p=261
First, load the Computer Management tool by running compmgmt.msc from the run menu (Press WINDOWS KEY + R to load this).
Then click on Disk Management on the left hand menu to bring up a selection of your current drives.
Right click on the drive that you wish to change the letter of, and select Change Drive Letter and Paths.
Click Change on this screen to select a new drive letter.
Now, choose a new drive letter for your device and click OK.
If you want to swap drive letters around, you'll have to rename one of the drives to a 3rd temporary letter to create space in the letter allocation.