how to patch SQL 2005 32bit express from SP3 to SP4 on 64bit OS

I downloaded SQLServer2005SP4-KB2463332-x64-ENU and X86 patched and ran both of them, The SQL instance name was showed in the setup screen, but I can't select it as database services to be upgraded. Somebody can help?

9.00.4035.00SP3Express Edition

Thanks

David