[KaCaT]

Before you install the bot, go to create a game in CS, then quit it (this will create the mp.dll which is needed by bots).

After you installed the bot, open liblist.gam in cstrike folder with notepad, replace
gamedll "dlls\mp.dll"
with
gamedll "ivpbot\ivpbot.dll"
Then, save the file and set its attribute to "Read-Only" mode by Right-Click on liblist.gam -> choose Properties from the menu -> Select Read-only from the General tab.