[KWo]

According to which kind of server You want to start (dedicated - standalone PC - or listenserver - You are playing from it by starting and creating the game), You need to work on such folders:
a) for dedicated server-
...\Steam\steamApps\your@email\dedicated server\cstrike
and here You need to find liblist.gam and replace the line with:
gamedll "dlls\mp.dll"
by this one
gamedll "addons\metamod\dlls\metamod.dll"
Note don't use semicolon (";") to comment out anything here. To comment out something (if need) just use "#" (without quotes).

...\Steam\steamApps\your@email\dedicated server\cstrike\addons
and here need to be placed 2 folders - metamod and podbot

b) for listenserver -
...\Steam\steamApps\your@email\counter-strike\cstrike
and here You need to find liblist.gam and replace the line with:
gamedll "dlls\mp.dll"
by this one
gamedll "addons\metamod\dlls\metamod.dll"
(with notes as above)
...\Steam\steamApps\your@email\counter-strike\cstrike\addons
and here need to be placed 2 folders - metamod and podbot

Note -after steam reinstall Your liblist.gam may be overwritten by it, so - even if it was working for You before, it may stop after reinstall. Just need to do re-edit it again (as explained above).
Hint:
And upgrade Your metamod to 1.18 version.