Ext HD & Plextor Burner both changed drive letters

[bjswaim]

Both my external hard drive and Plextor burner changed drive letters. The external hard drive was F and the Plextor was E. Now the external hard drive is E and the Plextor is F. Hence, I can't open Hoster because my songs are on my external hard drive which was F. How do I change the drive letters back to where they were? I tried going into "my computer" and right clicking on the drive and selected "rename" but when I change the letter it then includes both letters in the name. Any help would be much appreciated since I can now no longer open Hoster.