[InstallShield 2012 Spring - InstallScript MSI - built and installing 32-bit app on Windows 7 64-bit] At the start of the feature install, I'm having a fatal 1639 error, which is a command line argument problem. I've tracked it down in the logs and it's obvious what's going wrong, but not why. [CODE] 00020: (Unknown): ******* CommandLine: [some properties...] ADDLOCAL=Feature1,Feature2,Feature3 ="" ALLUSERS=1 [more properties...] [/CODE] So InstallShield seems to be generating this no-name, no-value property that it's feeding to the Windows Installer through the command line. The Windows Installer properties are delivered in alphabetical order, and I've found this list of properties in MSDN docs: http://msdn.microsoft.com/en-us/library/windows/desktop/aa367538(v=vs.85).aspx The following properties occur alphabetically between ADDLOCAL and ALLUSERS, so it seems like it should be one of these. On the other hand, none of them really make sense to be the problem. ADDSOURCE - Can be in Property table, but it isn't there in my project and docs say not to put it there. AdminProperties - Belongs in Property Table, but I don't use it so it's not present. AdminToolsFolder - Docs say "If the ALLUSERS Property is set (which it is), this property points to the file system directory that contains the administrative tools for all users of the computer." I don't have this property set, but I have another project with the same situation (ALLUSERS is set, but not AdminToolsFolder) and there's no problem. AdminUser - The article talks mainly about Vista (not relevant), but basically this is set at run time so it shouldn't be something I'm breaking. Advertise -Like ADDSOURCE, can be in the Property table, but it shouldn't be, and it isn't. AFTERREBOOT - Added by the installer after a reboot takes place, which isn't happening. Unfortunately these installer properties aren't simply listed in InstallShield, other than where noted. I have no fear of modifying tables with the Direct Editor in IS, but I simply have no idea what IS table values are used to create most of these corresponding Windows Installer properties. I've done my best to browse through the tables looking for blank entries, but I haven't been able to find anything that looks out of place. It might even be the case that some well formed property indicates to IS that there should be some other property-value pair which does not in fact exist (such as ALLUSERS to AdminToolsFolder). I've tried my best on this but the trail's gone cold. Any ideas? Ps. I also found this related post from years ago, which has the same symptoms: http://community.flexerasoftware.com/showthread.php?187535-Error-quot-the-wizard-was-interrupted-before-could-be-completely-installed-quot&highlight=1639 ... View more