Spotlight search is not working. I am searching for a file that I know is on my computer but Spotlight can’t find it.

After updating Mac computers to OS 10.11, the drive will need to be re-indexed to optimize searches. This should happen automatically after the update and can take up to 45 minutes to complete.

If Spotlight stops working, you can force Spotlight to re-index your hard drive with the following process: 

1. Select the Apple menu in the upper left corner of your screen and choose System Preferences.
2. Click Spotlight in the top row.
3. Select the Privacy tab.
4. Click the "+" (plus) sign in the lower left region of the window.
5. Select Macintosh HD from the side bar and click Choose.
6. You will see the following prompt. Click OK.
   
7. Select the Search Results tab, and then click back to the Privacy tab.
8. Highlight Macintosh HD and click the "-" (minus) sign in the lower left region of the window.
9. Close out of the Spotlight window.
10. In the upper right corner of your screen, click on the Spotlight magnifying glass. A drop down window will display that spotlight is reindexing your drive and, after a few seconds, display an estimate of the time it will take to complete the process.