Issue :- SEP Client Install roll back on Windows Vista Enterprise Machine . (SEP 11) Sep Install log :- MSI (c) (8C:24) [12:02:40:166]: Invoking remote custom action. DLL: C:\Users\ADMINI~1.TEA\AppData\Local\Temp\MSI6C91.tmp, Entrypoint: CheckInstallPath Action ended 12:02:40: CheckInstallPath. Return value 3. Info 2896.Executing action CheckInstallPath failed. Action ended 12:02:40: InstallWelcome. Return value 3. MSI (c) (8C:34) [12:02:40:201]: Doing action: SetupCompleteError Action 12:02:40: SetupCompleteError. Action start 12:02:40: SetupCompleteError. Action 12:02:40: SetupCompleteError. Dialog created Solution In Windows Vista Open Control Panel Open Regional and Language Options Under 'Current Formats' select 'US English' Click OK Should be able to install Sep 11