1. From the Apple menu, choose System Preferences.
2. Click Spotlight.
3. Click the Privacy tab.
4. Drag a file, a folder, or even an entire volume (your hard drive) to the list.
5. Remove the item or volume you just added.
Spotlight will re-index the contents of the item you initially dragged to the list.
It won't let me add my hard drive, a file or a folder to the privacy tab so that I can erase it and let it reindex.