Ok. Are you trying to start dedicated server or installing metamod on listenserver?
If you are starting dedicated server through steam, follow as (mm installed):
1. Open Steam game list.
2. Select Dedicated Server and click right button and select Properties from list.
3. Open 'Set launch options...'
4. Write '+log on +localinfo mm_debug 10' to edit area (without ').
5. Close properties windows and start server.
If you are running server from within game (listenserver), follow as (mm installed):
1. Open Steam game list.
2. Select Half-Life and click right button and select Properties from list.
3. Open 'Set launch options...'
4. Write '+log on +localinfo mm_debug 10' to edit area (without ').
5. Close properties windows and start server.
Then post results here.
(If you are running dedicated server without steam add '+log on +localinfo mm_debug 10' on startup line or in shortcut with hlds.exe)
If you check your Half-Life/valve/dlls-directory and it's empty or doesn't exists, copy following file there:
http://koti.mbnet.fi/axh/jk_botti/hl.dll
So you will have Half-Life/valve/dlls/hl.dll
If you get server running with copying this file in, go remove those launch options (will slowdown server).