SoapUI 4.5 maybe others use install4j type of installer. http://resources.ej-technologies.com/install4j/help/doc/help.pdf

here is some of the info i found helpfull.....adjust to your needs

Installers generated by install4j recognize the following command line parameters:

http://resources.ej-technologies.com/install4j/help/doc/indexRedirect.html?http&&&resources.ej-technologies.com/install4j/help/doc/helptopics/installers/options.html

Silent

soapUI-Pro-x64-4.5.1.exe -q

Silent  with progress bar

soapUI-Pro-x64-4.5.1.exe -q -splash title

Silent with progress bar and response file

soapUI-Pro-x64-4.5.1.exe -q -splash title -varfile response.varfile

note: if you install manualy first you can grap the response file from c:\program files (x86)\SmartBear\soapUI-Pro-4.5.1\install4j\response.varfile (eg install directory\install4j\responsfile)

soapUI-Pro-x64-4.5.1.exe -q -splash title