[dnanian]

Bart:

Run the following command in Terminal (copy/paste):

sudo mdutil -E -i on /

Press Return at the end if you must, and enter your password when prompted (it won't echo), pressing Return at the end of that, too.

Soon after, Spotlight should commence indexing the drive.

Hope that helps!

(Note -- this assume that you're *booted from* the drive you wish to restart indexing on.)