Codesigning is an advanced topic. Please refer to wiki for details. Briefly: you can order a code sign certificate to codesign your .exe/.dll/.ocx files. Codesigning will sign these files with your certificate and mark them as yours. It is also used to avoid true-false detections from AntiVirus software, since AV software trust codesigned files more.
It is possible to use self-signed certificate but this is not recommended at all. You can purchase a genuine codesign certificate for example from comodo or simple search google by “purchase codesign certificate” and choose your preferred CA.
We recommend for all our clients to use CodeSigning certificate but this is matter of budget because price starts at 90$ per year and up depending on features.
You can either define one of predefined TimeStamp Servers (required) and certificate password (recommended). MetaSetup requires the certificate in .pfx format to be present in order to use it. Once setuped hit “Test” button to test your configuration. Once Codesigning has been enabled and tested, MetaInstaller, MetaLoader and Uninstaller will be code signed with your certificate. Additionally you can choose particular .exe/.dll/.ocx files to be code-signed as well. In order to do this, click to Files, double click the file and inside “Properties” tab check “Codesign this file” box. Only .exe/.dll/.ocx (executables) files can be codesigned at this time.