[UncleMonty]

Spotlight is failing to index an external harddrive. It indexes up to 9% (with four hours remaining) and then gets stuck.

What I can do to try to get it to work?

[osiris24x]

This can generally be fixed by resetting Spotlight's index for that particular drive. This can be done in Terminal by typing: "sudo mdutil -E /Volumes/DriveName", replacing DriveName with your particular drive's volume name.

You might also check that the drive isn't having any issues, with Disk Utility.