Unattended Installation: Differences Between MSI and EXE Files
Tactical Software offers its installation programs in MSI and EXE files.Please contact support@tacticalsoftware.com if you require MSI filesUpdating Using EXE FilesEXE files are the preferred method for installation, as they are able to detect an existing version of the software and offer the user the option of uninstalling the existing product.MSI files do not have this ability and will instruct the user to use the Add/Remove Programs on the Windows Control Panel to remove the existing product first.In many situations, the EXE files combined with pre-configured command-line options would be preferred, especially if /qb is used. The /qb option eliminates dialogs from the GUI that enable the user to override how the product is installed.The only problem with using EXE files arises when deploying an unattended installation/upgrade. There is no way to instruct the EXE file to uninstall the existing version without first prompting the user.Updating using MSI filesTo implement an unattended upgrade, the MSI file must be used.Given this limitation, using the MSI file should only be done if it is a requirement that future installations be completely silent. In a completely silent install, the installer is prevented from notifying the user of critical failure conditions such as a COM port being in use. In this situation, the installation will simply do nothing, and there will be no notification that there was a problem.The /fvams option tells the Windows Installer to treat the MSI file as an upgrade.For example, to replace the existing version of DialOut/EZ Site Edition with the version found in the MSI file, use following command line:
msiexec /fvams DialOutEZSiteEdition.msiA silent upgrade command line would be: msiexec /q /fvams DialOutEZSiteEdition.msiThis technique has the following limitations:The EXE and MSI packaging cannot be mixed and matched if /fvams will be used at a later date. If the product has been installed using the EXE, and then /fvams is attempted as the mechanism for upgrade, the installation will fail with an error.The /fvams option cannot be used to perform a first-time installation of the product. This could lead to complications when deploying to a large number of desktops where some of the desktops already have the software but others do not.The name of the MSI file specified via /fvams must be the same filename that was used to install the product originally. This is why the version number of the product is not included in (and should not be added to) the filename of the MSI file.The /fvams upgrade cannot be used to change the feature set (such as adding or removing Administrator Only Mode).