How can I change the root directory letter of a drive?

For example, my external drive from drive ';E'; to drive ';F';.How can I change the root directory letter of a drive?
RIGHT-CLICK MY COMPUTER%26gt;%26gt;MANAGE%26gt;%26gt; Under STORAGE%26gt;%26gt;DISK MANAGEMENT%26gt;%26gt;RIGHT CLICK ont he DRIVE LETTER you want to change.How can I change the root directory letter of a drive?
That would be correct, if you are using XP