Hal,

If you are using SignCode.exe (the default option) then you need the .SPC and .PVK files.

If you switch to SignTool.exe then you need a .PFX file! It says "optional" because the use of SignTool.exe is optional.

So your SignTool.exe is okay (if you have downloaded the file from Microsoft and the path to it has been added in Tools | Options... | File Locations -> Digital Signature. The next step is to use your .PFX file and you are done

Does this help?

Friedrich