Changing Drive Letters
To change the default letter assignment for drives:
1 Right click [My Computer]

2 Click [Manage] to open the Computer Management Console
3 In the top or lower right pane, right click the disk you want to change.
4 Fixed drives appear in the top and bottom pane. Removable drives appear in the bottom pane unless they have media inserted in which case they appear in both the upper and lower pane.

5 Select [Change Drive Letter and Path]
6 Click [Change]
7 Select the new letter from the drop down list box and click [OK]

- srikanth dhanwada