Improving Windows Desktop Search for PDF and Other Binary Files

Windows Search, formerly Windows Desktop Search, may not index content and metadata of binary files, such as, those of PDF files without assistance of some additional software although it does index the files based on their names.

To enable Windows Search to index content and metadata of binary files, we need to install some additional software to help the Windows Search. Windows Search supports iFilter. With the matching iFilter add-in installed, Windows Search can index content and metadta of binary files of certain types. The iFilter.org site lists a number of iFilter add-ins for a few types of binary files, e.g., ZIP, CAB, CHM, DjVu, and PDF files.

Below we show how we can enable indexing content and metadata of  PDF files.

First, we can check whether PDF iFilter exists. The following steps are carried out on a Windows 10 host.

1. Open "Windows Control Panel"
2. Search and open "Indexing Options"
3. Open "Advanced" from "Indexing Options" 
4. Choose "File Types"
5. Locate the "pdf" file type.
   
   
   
   
   
   Above figure shows that "Registered iFILTER is not found", which means that iFilter add-in is not installed and Windows Search do not index content and metadata of PDF files.

To enable indexing content and metadata of PDF files, we can choose and install Adobe PDF iFilter. If the PDF iFilter is installed, repeating the above step, Windows will indicate that the iFilter is intalled as illustrated in the figure below.

 To force Windows Search to index content and metadata of PDF files immediately upon the  installation of the PDF iFilter, we can check and uncheck PDF file types from the "File Types" tab of the "Advanced Options" of the "Indexing Options" as follows,

1. Open "Control Panel", "Indexing Option", then "Advanced Option", and finally, the "File Types" tab
2. Locate the "pdf" file type
3. Uncheck the "pdf" file type
4. Click "OK"
5. Window pops up a dialogue window stating "Rebuilding the index might take a long time to complete. Some views and search results might be incomplete until rebuilding is finished." Click "Cancel" on this dialogue window.
6. Windows will return to "Indexing Option". Now click on "Advanced" again to open the "Advanced Options"
7. On the Advanced Options, choose "File Types"
8. Locate the "pdf" file type again
9. Check the "pdf" file type
10. Click on "OK" to confirm
11. Window now pops up again the dialogue window stating "Rebuilding the index might take a long time to complete. Some views and search results might be incomplete until rebuilding is finished." Click "OK" on this dialogue window to confirm. Windows starts rebuilding the index. Depending on the amount files on the disk, it may take a long time to rebuild the index. 
12. You can safely close the "Indexing Option". Windows index continues to rebuild the index in background.