Sorry für die kleine Pause, hatte viel um die Ohren und keine Zeit für meinen WSUS.
So, habe nun erneut einen frischen 2003 Server SP2 aufgesetzt, alle Systemvoraussetzungen gem. Anleitung hergestellt und erhalte den selben Fehler.
Das WSUSSETUP.LOG enthält dies:
2010-12-22 15:03:41 Success MWUSSetup Validating pre-requisites...
2010-12-22 15:03:42 Error MWUSSetup Failed to determine if an higher version of WSUS is installed. Assuming it is not... (Error 0x80070002: Das System kann die angegebene Datei nicht finden.)
2010-12-22 15:03:42 Error MWUSSetup WSUS is outdated. But this will not block setup (Error 0x00000000: Der Vorgang wurde erfolgreich beendet.)
2010-12-22 15:04:34 Success MWUSSetup No SQL instances found
2010-12-22 15:05:35 Success MWUSSetup Initializing installation details
2010-12-22 15:05:35 Success MWUSSetup Installing ASP.Net
2010-12-22 15:05:55 Success MWUSSetup ASP.Net is installed successfully
2010-12-22 15:05:55 Success MWUSSetup Installing wYukon using MSI on Win2k3
2010-12-22 15:05:55 Success MWUSSetup Installing wYukon...
2010-12-22 15:07:27 Success MWUSSetup wYukon Installed Successfully
2010-12-22 15:07:33 Success MWUSSetup Installing WSUS...
2010-12-22 15:07:35 Success CustomActions.Dll Unable to get INSTALL_LANGUAGE property, calculating it...
2010-12-22 15:07:35 Success CustomActions.Dll Successfully set propery of WSUS admin groups' full names
2010-12-22 15:07:37 Success CustomActions.Dll .Net framework path: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
2010-12-22 15:07:38 Success CustomActions.Dll Creating user group: WSUS-Berichterstatter with Description: WSUS-Administratoren, die nur Berichte auf dem Windows Server Update Services-Server ausführen können.
2010-12-22 15:07:38 Success CustomActions.Dll Creating WSUS-Berichterstatter user group
2010-12-22 15:07:38 Success CustomActions.Dll Successfully created WSUS-Berichterstatter user group
2010-12-22 15:07:38 Success CustomActions.Dll Creating user group: WSUS-Administratoren with Description: WSUS-Administratoren können den Windows Server Update Services-Server verwalten.
2010-12-22 15:07:38 Success CustomActions.Dll Creating WSUS-Administratoren user group
2010-12-22 15:07:38 Success CustomActions.Dll Successfully created WSUS-Administratoren user group
2010-12-22 15:07:38 Success CustomActions.Dll Successfully created WSUS user groups
2010-12-22 15:07:38 Success CustomActions.Dll Succesfully set binary SID property
2010-12-22 15:07:38 Success CustomActions.Dll Succesfully set binary SID property
2010-12-22 15:07:38 Success CustomActions.Dll Successfully set binary SID properties
2010-12-22 15:10:46 Error MWUSSetup InstallWsus: MWUS Installation Failed (Error 0x80070643: Schwerwiegender Fehler bei der Installation.)
2010-12-22 15:10:46 Error MWUSSetup CInstallDriver:

erformSetup: WSUS installation failed (Error 0x80070643: Schwerwiegender Fehler bei der Installation.)
2010-12-22 15:10:46 Error MWUSSetup CSetupDriver::LaunchSetup: Setup failed (Error 0x80070643: Schwerwiegender Fehler bei der Installation.)
2010-12-22 15:34:58 Error MWUSSetup CWatsonHelper::Init: Failed to load WER library. (Error 0x8007007E: Das angegebene Modul wurde nicht gefunden.)
2010-12-22 15:34:58 Error MWUSSetup CSetupDriver::ReportFailure: Failed to initalize the CWatsonHelper. This is expected on pre-Vista machines. (Error 0x80004005: Unbekannter Fehler)
2010-12-22 15:34:58 Error MWUSSetup DoInstall: Wsus setup failed (Error 0x80070643: Schwerwiegender Fehler bei der Installation.)
Ich habe bald keinen Bock mehr