As you probably know searching is the most efficient way to find documents, applications, and settings in Windows 7 and 8. By clicking on the Start button and typing you can quickly find files containing specific text and phrases.
The mechanism that allows this is Windows Search that runs as a Windows service. Windows Search has it’s roots in the Indexing Service that first appeared in NT4 and Internet Information Services (IIS). Indexing involves building a catalog (index) that contains the meta-data for files and applications. The meta-data is retrieved via plugins called IFilters.
Windows Search by default includes IFilters for common filetypes, including Word documents, Excel spreadsheets, PowerPoint presentations, HTML files, text files, MP3 and WMA music files, WMV, ASF and AVI video files and JPEG, BMP and PNG images. PDF files are indexed by Windows Search using an IFilter installed automatically when Adobe Reader is installed. However, on 64-bit versions of Windows the IFilter is not installed and the Indexing Service is unable to parse and index these files. Fortunately, the fix is easy and can be done without a reboot.
First, to confirm the IFilter is not installed you need to open Indexing Options in the Control Panel. To do this click on Start and enter the text index. Windows will search for anything with “index” and display the Control Panel option Indexing Options.

When selected the Indexing Option window appears. This window tells you the status of the Indexing Service, the number items in the catalog, and the options to add or remove search locations. In the following example my computer has indexed 12,033 items.

Click on the button Advanced and then click on the tab File Types. Scroll down to the PDF extension. If the IFilter has not been installed the filter description will state Registered IFilter is not found as in the following screenshot:

After confirming the IFilter is missing you can close the Indexing Options window and download Adobe’s IFilter for 64-bit Windows. The current version as of the time of this writing is PDF iFilter 64 11.0.01 and can be downloaded from Adobe’s HTTP site or FTP site.
Once downloaded, you can install it using an elevated command prompt (run Command Prompt as administrator) with the following command:
msiexec /i “C:\Install\PDFFilter64Setup.msi” REBOOT=R /qb /L*v c:\temp\install_ifilter.log
After the installation completes go back into Indexing Options and confirm the IFilter was installed and registered. The following screenshot shows that the Indexing Service will use an IFilter named “PDF Filter”.

Now, all that is left to do is to rebuild Windows Search index. Click on the Index Settings tab and then on the button labeled Rebuild.

After clicking the Rebuild button Windows will display a warning, click OK to start the rebuild.

The status of the rebuild can be monitored on the Indexing Options window. While you are using your computer Windows will reduce the speed of the indexing operation.

Eventually (within an hour or two, depending on size of catalog) the index will be rebuilt and now contain search items from PDF files. On my computer the number of indexed items increased to 40,913.
