Vista - disk management not loading

i'm trying to follow this tutorial Drive Letter - Add, Change, or Remove.
however, once i've opened computer management, clicking data management produces only this:
http://i33.tinypic.com/149nxa8.jpg

it never loads.

am i doing something wrong? help would be appreciated!

edit: not sure what happened, but it loaded all of a sudden.
i think it had to do with my SD card being in, not sure why.

while i have a thread made, i might as well ask this:
are there any risks for renaming my drives?
my USB drive is K and dvd is F, but i'd like to switch the two.
would there be any complications?