1 Make a folder in your HL root catalog, name it whatever you like the mod to be named, this is where all your mod files are going to be.
2 Copy your Liblist.gam from your Half-lifevalve folder, put it in the folder you created in step one.
3 Open the Liblist.gam file with an text editor and edit the following strings:
game "YOURGAME" -self explanatory, the name of your mod.
startmap "YOURMAP" -the map that will load when you choose new game.
trainmap "YOURMAP" -the map that is going to load when you choose hazard course.
gamedir "YOURDIR" -the directory name that you created in step one.
url_info "YOURWEBPAGE" -if you want to a link to your mod?s homepage.
version "YOURMODVERSION" -the version of your mod.
type "DESCRIPTION" -description of your mod.
gamedll "dllsYOURDLL" -the dll-file the game should load.
mpentity "YOURENTITY" -the MP entity players should spawn from.
this should solve your problem.
by the way..........
"I wanna learn c++ in ONE lifetime" :P