Presetup=<program>
SFX will try to execute <program> before starting extraction, so <program> must already exist on disk. The destination folder is set as the current before executing <program>. You may use this command, for example, to remove a previous version of program, when installing a new version over the old one. If a program name contains spaces, it must be enclosed in quotes.
Presetup=uninstall.exe /clean