Every so often you may need to delete the spotlight index or rebuild it. There may be a variety of reasons, for example if you clone your hard drive and spotlight isn’t picking up every file or folder, or you believe that you can’t find the file you want when you do a spotlight search. Rebuilding the index is simple, and it doesn’t take long for spotlight to be up and running again.
To rebuild your index open up System Preferences > Spotlight. Then open up the privacy tab. Normally you would place files or folders in this area that you don’t want to be indexed. To rebuild the index drop your hard drive from Finder into this window.
Repeat this for as many hard drive you have or want to re-index. Once you have done this, select the drive and press the minus button from the bottom of the list. This will delete the delete the hard drive from the privacy options and force spotlight to remove and start re-building the index.
The re-indexing will start a second or two after you delete the hard drive from the list. It will then proceed to rebuild the index. Depending on how many files you have it may take a while to update.