I have Vista Ultimate x64. I just went online and purchased WinZip 12.1 Standard. I can get it to download to my desktop just fine, but whenever I try to run the .EXE application, it says "Starting Windows Installer" and then the screen fades and my computer shuts down. Over, and over, and over. I know this software is compatible with Vista, so what is the issue? BTW, User Account Control is disabled, and I am Administrator.