Changeing Drive Letters In Windows XP Home
Sometimes it becomes necessary, or desireable to change the drive letters on your computer.
The steps for doing this are outlined below.
NOTE:
When making any major changes to your system, make sure you have backed up your files, and set a system restore point first.
Changeing the drive letter of the drive, or drives containing the operating system and program files is not recommended.

1. Open the Control Panel, and select, Administrative Tools, and press enter.
2. From the available options, select, Computer Management, and press enter.
3. When this window opens, arrow to, storage, and then to, disk management, and 
then tab once to get a list of drives on your computer.
4. From the list of drives, use the up and down arrow keys to select the one you wish to change the letter of
Note:If you wish to change, for example:
drive D, to drive E, and E is already in use, you will need to change the letter of drive E, to an unused letter first, so that the letter E will become available.
5. Once you have the appropriate drive selected, open the menu bar, and right arrow to the, action menu.
6. Here, arrow down to the, all tasks, sub-menu, and press enter to open it.
7. When this menu opens, arrow to, change drive letter and paths, and press enter.
8. When this dialogue opens, the drive you selected will be shown, so tab to the, change button, and press the spacebar.
9. When this dialogue opens, assign the following drive letter, will be checked, so tab once
and you will be in a combo box of available drive letters.
10. Select a, drive letter and then tab to the okay button, and press the spacebar. 
11. Next, you will get a confirmation message, so press the spacebar to confirm.
12. Press alt F4, to close all windows, and then re-boot the computer to make sure that all changes take affect.
You are done
NOTE:
When changeing the drive letter of a cd drive, a cd must be in the drive, so that the drive contains a volume.
If there is no disk in the drive, it will not show up in the list of drives in, disk management.
If you wish to change a letter for a cd drive, do the following.
Insert a cd into the drive and close the drawer, and hold down the shift key to by-pass the auto-run feature.
Next, follow the steps outlined above to change the drive letter.