Check or change PDF preview handler and IFilter
Question / Problem
How can I check which preview handler and which IFilter is currently in use for PDF files? Considering some of these work better than others, can I change the used ones?
Answer / Solution
The easiest way to see and possibly change the registered preview handler or IFilter (used for the file content search) for PDF files is to install the free version of PDF-XChange Editor which comes with a lightweight separate tool for this exact purpose.
You can find it under "C:\Program Files\Tracker Software\Shell Extensions\XCShInfoSetup.exe" when using the default installation path.
TreeSize and UltraSearch both use the preview handler and IFilter that is registered as default in the system, which is what you can see and adjust in this small tool.