Hello... i've just discovered the bitdefender's 2009 silent install Just follow the steps : 1. Extract bitdefender 2009 with universal extractor , winrar or what decompressor you like. 2. If your building an unattended cd or dvd and want to install applications using WPI (Windows Post Installer) , add this line in WPI : msiexec.exe /i "bdts.msi" /qb That's all. Worked for me P.S. : For normal install , it's the same . Extract bitdefender ( bitdefender must be extracted , otherwise it won't run! Open ms-dos , you input the command line : msiexec.exe /i "bdts.msi" /qb and your done. (I got some errors during install ...about some registry keys...Just hit the ignore button in you have the same problem.)