Remember: . It often worsens corruption. Instead, methodically diagnose using Event Viewer and the WinCC Diagnosis Tool. With patience and the steps above, you will identify the root cause and implement a permanent fix. Last updated: For WinCC V7.5 SP2 and later. Always refer to Siemens official documentation for your exact version and patch level.

By systematically working through this guide – starting from Windows services, moving to permissions, then DCOM, and finally repairing the installation – you can resolve the error and restore your SCADA system to full operation.

Windows had installed a security update that changed DCOM permissions and disabled MSDTC service.