I tried on NT after I tried on Solaris and failed..

Check this out
on NT 4.0 Oracle 8i

C:\>lsnrctl

LSNRCTL for 32-bit Windows: Version 8.1.6.0.0 - Production on 05-DEC-2000 15:50:52

(c) Copyright 1998, 1999, Oracle Corporation. All rights reserved.

Welcome to LSNRCTL, type "help" for information.

LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC0)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 8.1.6.0.0 - Production
Start Date 04-DEC-2000 12:59:41
Uptime 1 days 2 hr. 51 min. 26 sec
Trace Level off
Security OFF
SNMP OFF
Listener Parameter File E:\Oracle\Ora81\network\admin\listener.ora
Listener Log File E:\Oracle\Ora81\network\log\listener.log
Services Summary...
PLSExtProc has 1 service handler(s)
cdn has 1 service handler(s)
cdn has 2 service handler(s)
mydb1 has 1 service handler(s)
The command completed successfully
LSNRCTL> dbsnmp
Ambiguous text "dbsnmp", valid completions are:

dbsnmp_start dbsnmp_stop dbsnmp_status

LSNRCTL> dbsnmp_status
The db subagent is not started.
LSNRCTL> dbsnmp_start
LSNRCTL> dbsnmp_status
The db subagent is not started.
LSNRCTL> dbsnmp_start
LSNRCTL>


Why is it unable to start??