You must uninstall the WMI performance counter provider and the WMI SNMP provider separately.
To uninstall the WMI performance counter provider
At the command line, type:
mofcomp <CD Drive Letter>:\winnt\wmi\deletebackupexecperfmon.mof
To uninstall the WMI SNMP provider
Smi2smir /d Backup_Exec_MIB