Default PDF reader

It is not feasible to set PDF Compare as your default PDF reader, because PDF Compare requires to PDF files to be opened each time you launch the software. No command line parameter is accepted by PDF Compare software.

If you are looking for a fast and reliable PDF Reader as your default PDF reader, you may consider PDF Reader for Windows 10,

http://www.pdften.com/reader.html

To set the software as your default PDF reader, simply click the menu item,

Tools->Set As Default PDF Reader

If you encounter the following error message, it means that you do not have enough privilege to complete this operation.

You can close the PDF Reader for Windows 10 program, and right-click the icon of this program on your Desktop, and then choose 'Run As Administrator' to launch the program with elevated privilege, and you will be able to set this program as your default PDF reader.

To set PDF Reader for Windows 10 as your default PDF reader from the command line, you can simply run,

PDFReader.exe /setdefault

To restore your previous default PDF reader, you can run,

PDFReader.exe /restoredefault