Disable Spotlight Index on 10.8 on Specific Volumes
From terminal type:

sudo mdutil -i off [mountpoint]


If you need to remove the index cache of a network drive that has been stored locally, then use the -p flag. Likewise, to remove the local cache of a locally attached volume, use the -E flag.

If you want to delete from /BOOTCAMP then you would use:

sudo mdutil -Ei off "/Volumes/BOOTCAMP"


NOTE: Quotations around the mountpoint of the volume are unnecessary if there are no spaces in the volume name or mountpoint. Otherwise you would need to use an escape character \ before each space.

e.g. sudo mdtuil -Ei off /Volumes/Macintosh\ HD for "Macintosh HD"