Copied from
http://www.symantec.com/connect/blogs/uninstall-setupexe-isuninstexe
If any vendor app is using Isuninst.exe for the app uninstall, you will find some useful command line parameters attached.
The silent mode parameter for Isuninst.exe is -a.
The complete uninstallation command for the Windows client is:
Sample: C:\WINDOWS\Isuninst.exe -a -f "C:\Program Files\F-Secure\Ssh\Uninst.isu"
Uninst.exe Command Line Parameters
The command line parameters for uninst are listed below:Parameter:
-y Suppresses the message box that asks the user to confirm that uninstallation should proceed. The feedback dialog box is still displayed, as is the shared file dialog box (which is displayed when the reference count of a shared DLL is decremented to zero).
-x Deletes all files, including those core components that normally do not get removed. (All user interface elements are displayed.)
-f<log file name> Specifies the location and name of the uninstallation log file.
For example: -f"C:\Program Files\Company Name\Uninst.isu"-c<DLL filename> Specifies the location and name of the external DLL that is to be used at the time of uninstallation.
For example: -c"C:\Program Files\Company Name\Custom.dll"-a Runs the uninstaller in silent mode. In this mode unInstallShield will not display any messages to the end user indicating that the uninstallation has taken place. When running in silent mode, if unInstallShield encounters a shared file for which it would normally display the dialog box asking the user whether to remove the shared file, it will automatically reduce the reference count to zero and not remove the file. Therefore, running unInstallShield in silent mode is functionally equivalent to an uninstallation in which the user selects the "No to all" option when this dialog box first appears.
-d Identifies a single file that is to be deleted. The display of user interface elements is the same as when the -a switch is used.
For example: -dC:\Temp\Filename.ext-m Creates an uninstallation .mif file. If you do not specify a filename, the default (Uninst.mif) is used. You cannot specify a path-the file must be placed in the Windows System folder.
