Just for the record: I solved the problem by checking myself whether the user 'postgres' actually exists before running the msi installer. I do this by running the following WSH script doing an ADO query: Private Function userExists ( ByVal domain, ByVal username ) ' checks whether a certain user exists ' see http://www.microsoft.com/technet/scriptcenter/resources/qanda/sept05/hey0907.mspx On Error Resume Next Set objUser = GetObject("WinNT://" & domain & "/" & username) If Err.Number = 0 Then WScript.Echo "The user account '" & username & "' exists in the domain '" & domain & "'" userExists = 0 ElseIf Err.Number = -2147022676 Then WScript.Echo "The user account '" & username & "' does not exist in the domain '" & domain & "'" userExists = 1 Else WScript.Echo "The user account status of '" & username & "' in domain '" & domain & "' could not be determined" userExists = 2 End If End Function WScript.Quit(userExists(args(0), args(1))) Explanation: Whenever this script exits with 0, the user does exists, and I set CREATESERVICEUSER=0, otherwise 1. If anyone knows about a more elegant solution, please let me know. Regards, Dirk. pgsql-admin-owner@xxxxxxxxxxxxxx schrieb am 18.06.2007 09:09:59: > Hi, > > the msi installer for Windows automatically creates a user 'postgres' if > CREATESERVICEUSER=1. Is it possible to do the following: > > 1) don't create the user, if it already exists, and continue with > installation, instead of showing the error message 'user postgres already > exists'. > > 2) during uninstallation, delete the user 'postgres' automatically, when > it has been created during installation. > > Thanks, > Dirk Moebius -- Dirk Moebius Software Consultant MBB Gelma GmbH, Bonn, Germany http://www.mbb-gelma.de/