I found this on this site. in case you havent seen it. It worked for me. Try this:
When I disconnected my backup drive and plugged in a USB drive the other night, my Windows drive letters got all wonky. D: became G: became F: became H:, and a bunch of my shortcuts didn't work anymore.
But it's easy to reassign the drive letters of your choice to add-on disks in Windows. Microsoft says you should log on as an administrator, and from Administrative Tools in Control Panel:
Double-click Computer Management, and then click Disk Management in the left pane.
Right-click the drive, the partition, the logical drive, or the volume that you want to assign a drive letter to, and then click Change Drive Letter and Paths.
Of course things can get wacky if the disk is in use - by your computer or another on the network - so proceed with caution, you drive alphabetizer, you.
How to change drive letter assignments in Windows XP
Read More: Windows
, Hard Drives