Microsoft Knowledge Base Article 887420 describes the following symptoms:
When you try to upgrade your Windows 2000-based computer from Windows 2000 Service Pack 3 (SP3) to Windows 2000 Service Pack 4 (SP4), you receive an error message that is similar to the following:
Unable to write ScriptMaps metabase entry.
After you click OK, you then receive an error message that is similar to the following:
Failed to execute regsrv32.exe Error code: 5
After you click OK in the second error message, the SP4 installation process stops.
Note In certain cases, after you click OK in the first error message, the SP4 installation process is completed, but errors are written to the event log.