If you are currently looking for the command, try extracting the .exe using a tool like 7-Zip to find the MSI, or use the Universal Silent Switch: Setup.exe /s /v"/qn REBOOT=ReallySuppress"
For troubleshooting, always generate a log during the install: msiexec /i "ActivInspire.msi" /qn /L*V "C:\Logs\ActivInspire_Install.log" Conclusion activinspire silent install exclusive