Dude, it uses InstallShield. [edit1] After checking the installer again, the setup is wrapped with an InstallShield wrapper for the DemoShield menu. But you don't really need it to install it silently. This is what you have to do. 1. Using WinRAR, extract the files of the original installer. You will see a folder named "Installs", and the DemoShield files. 2. Go the the "Installs" folder and you will see a Wise setup.exe. 3. Type %temp% to your "Run" command. If you have a lot of files there, delete them to avoid confusion. 4. Run the setup.exe in the "Installs" folder to extract the msi file inside. Wait for the welcome screen of the installaiton of PowerDesk. 5. Go back to your %temp% directory and you will see an msi file inside. In my case, it is "c0cd6.msi" 6. Copy that file to a different location and exit the setup. 7. Install it using the regular msi switches. 8. For the registration, use PIDKEY=XXX-XXXXXXX-XXXX Example: PowerDesk6.msi /qb!- PIDKEY=XXX-XXXXXXX-XXXX Please try it and post back the result.