PDF Indexing Filter for native Windows10 applications


If you observe that pdf files will not be indexed in your libraries, you need to check for the correct Windows10 PDF Filter. This How-To is only for Win10 – Check other PDF IFilter article for Win7.

PDF Indexing: How-To Inspect and Change the Filter Handlers

First, open the PDF Indexing Options panel in the Control panel:

Control Panel for PDF Indexing Options

Control Panel for PDF Indexing Options

Now click on Indexing Options / Advanced / File Types. This shows you the list of file extensions and the default Filter Handler registered for it. After installing an Adobe Filter, you can see that it adds a Handler for PDF that it calls “PDF Filter”.

Installed PDF Indexing Filter

Installed PDF Indexing Filter

Any indexing of PDF content at this point will use the Adobe Filter. To get PDF indexing working with Windows10 Store Universal Windows Platform Apps like Noggle, you need to use the native Windows10 pdf filter which is already shipped with Windows10. To change it, you need to know the GUID for the filter. The please take a note now:

What’s the GUID for the naitive Windows10 UWP PDF Filter?

Adobe GUID: {E8978DA6-047F-4E3D-9C78-CDBE46041603}
Windows10 GUID: {6C337B26-3E38-4F98-813B-FBA18BAB64F5}

That’s great, but now what if you want to switch back and forth?

Default Handlers in the Registry

How do we find out where the Default handler is configured in the Registry? Open the registry editor by typing RegEdit in the windows search box and start the desktop command.

Let’s look at HKEY_CLASSES_ROOT.pdf. In my case, it contains a PersistentHandler sub-key. This GUID is a registry branch that defines the Filter Handler for PDFs.

RegEdit PDF Indexing GUID

Note: this GUID is not constant like the IFilter GUIDs are. Yours will be different.

So let’s take a look at {F6594…..382E} by searching for it. This brings us to HKEY_CLASSES_ROOTCLSID{F6594…..382E}:

RegEdit PDF Indexing Filter Handler

RegEdit PDF Filter Handler

And there it is, under PersistentAddInsRegistered, the (Default or Standard) key pointing to the Adobe GUID of {E8978DA6-047F-4E3D-9C78-CDBE46041603}. As you’ve probably guessed, to change the default handler to the native Windows 10 PDF handler, we just have to replace this GUID with the Windows10 GUID: {6C337B26-3E38-4F98-813B-FBA18BAB64F5}. Let’s try it.

RegEdit PDF Indexing Windows 10 IFilter

RegEdit PDF Windows 10 IFilter

Now let’s take another look at Advanced Indexing Options:

PDF Indexing Win10 Filter activated

PDF Win10 Filter activated

And we’re on the Windows10 “Reader Search Handler” for PDF indexing with UWP apps. That’s it!


Here is how the registry entries are structured to define the default or standard handler:

(Default)={PDF Handler GUID}
{Some other GUID}
(Default or Standard)={Filter GUID} <– Change this

Finally, you can check if the correct iFilter is available via the SearchFilterView Tool:

SearchViewFilter Tool

SearchFilterView Tool with correct Windows10 Filter handler activated for the extension .pdf



How To Article for Win7 / Desktop Apps:

Tool to check available filter components:

Technical Info from Microsoft: