When using quotes with the START command on Windows 7 with Outlook 2010, a new command window will open, but Outlook will not launch. This happens with the 32bit versions of Windows 7 Pro and Enterprise editions (both with the most recent updates). I can't say if it happens with 64bit versions or other editions.
To resolve that issue, you must omit any quotes that surround the "path\program" you're wanting to launch with the START command. However, since there are usually spaces in the path name, you'll likely receive a different error unless you truncate the path (shorten it). The truncated names in the path can vary if you have multiple Microsoft products installed. To obtain the correct truncated path, use the following command line at a DOS prompt (in a CMD window):
FOR /D %T IN ("C:\Program Files\Microsoft Office\Office14\Outlook") DO ECHO %~sT
Here is an example that worked for me when using the results obtained from above:
START /MIN C:\Progra~1\Micros~1\Office14\Outlook
NOTE: Office14 refers to version 2010 whereas Office12 refers to version 2007.
Also note that the .exe at the end of Outlook.exe is not required in these command lines.