When installing a new version of SMSMSE, after clicking the "Install" button on the "Ready to Install the Program" screen the installation stops and the following error message is displayed:
The wizard was interrupted before Symantec Mail Security for Exchange could be completely installed..
1. Open the SMSMSE installation log %TEMP%\SMSMSE_Setup.log in Notepad or another text editor.
2. Search for the string fnGetReinstallProductMsiProperties. If it is is present, this means the SMSMSE installer has detected a previous version and is attempting to perform an in place upgrade.
This error will occur if a previous installation is partially present but is too incomplete to perform an in place upgrade.
Manually remove any components of SMSMSE using the following article: Manual removal instructions for Symantec Mail Security for Microsoft Exchange, Symantec AntiVirus/Filtering for Microsoft Exchange, or Norton AntiVirus for Microsoft Exchange.
Once these steps are completed the installation should procede successfully.