When I try to do a silent install on a Windows 7 machine, using the command below, I get an error message that says, "Invalid command line argument". Using this same command on a XP machine works fine.
msiexec /i "C:\temp\Toad for Oracle 10.6 Commercial\Toad_Standalone\10_6_0_42\Toad for Oracle 10.6.msi"INSTALLDIR="C:\Toad_10_6\"ADDLOCAL=Client,Server /qn
Remove the "ADDLOCAL=Client,Server" portion of the command and just run...
msiexec /i "C:\temp\Toad for Oracle 10.6 Commercial\Toad_Standalone\10_6_0_42\Toad for Oracle 10.6.msi"INSTALLDIR="C:\Toad_10_6\" /qn
(Note: If you still issue with this resolution, run this command with /qn changed to /qb. This will give a pop up window during the installation, but will allow you to install Toad)