Here's another Mac Quick Tip to solve problems with Spotlight. Recently, I came across some things that Spotlight indexed but were no longer on my hard drive and had to find a way to force it to index my entire HDD again. It's quite simple actually.

Here's what you need to do:

1) Open System Preferences and click the Spotlight option;

2) Choose the Privacy tab where you can add locations you don't want Spotlight to index. Adding a location here, not only prevents results from that location to appear on searches, but it also deletes what was already indexed regarding that location. In my case, I wanted to do that to the entire disk, so I simply dragged my Macintosh HD icon from the desktop into there. You can do this to any folder, or disk;

3) Close System Preferences and open it again, Spotlight section, Privacy tab;

4) Select the location(s) you want to re-index and click the "minus" sign at the bottom of the list and then close System Preferences.

Wait a few seconds and you'll see the Spotlight icon in the top-right corner of the screen with a little dot in the middle. That means it's indexing. If you click it you can see the progress of the indexing process (it may take a while, depending on how much it has to index).

-João