Personal Information Exchange in digital signature

1- for digital signature; How to provide the Personal Information Exchange file (PFX or P12)
from a Certificate Authority?

2- Does installing Paquet Builder will eliminate appearance of the “Unknown publisher” from the warning message? or digital signature is must???

After you get your certificate, you should be able to export it from your web browser to a PFX file.

It’s the digital signature that will eliminate the “Unknown publisher" warning. Paquet Builder and XLS Padlock can digitally sign EXE files if you provide them with your certificate and private key in PFX format.