Obvious solution not mentioned by OP: disable WSC. “Security” gimmicks that nag user and are misused by malware authors in social engineering way to spread their rogue AVs are not really of much value to the users. Avast! has it own diagnostics, and so do all other decently written AVs. A diagnostics that does not rely on the heavily broken and flaky WMI thing.
WSC does not provide anything useful here in respect to protection.