Garena
You may need to add garena into firewall trust list
Disable UAC (Windows Vista)
Start the garena client and login, click left 4 dead under games and chose your location chat room
Click the setting button bellow the chat and browse your left4dead.exe
Game Bootstrap Parameters is -console -novid
Wen u click the start game button beside that setting button it will start left4dead.exe
Game will start whit console open -console and witout opening movie -novid
Clients
1.Host give ip in the chat, copy one and click the start game button
Game will start whit the console open so you can type connect (ip) to join
Type connect, make a space, use ctrl-v to past the ip you copy and press enter
Exemple : connect 192.168.29.86
2.You may see some friend in the left 4 dead menu try to click them and join there game
Host
To host you type those 5 line in console
sv_lan 1
sv_allow_lobby_connect_only 0
mp_gamemode versus
z_difficulty normal
map l4d_vs_hospital01_apartment
You have to press enter after each line, the hosting will start after the last line
To open the console press ~ (allow developer console need to be enable in option keyboard/mouse)
To know your ip type net_status in console
use alt-tab to come back garena and give your ip in chat
To change the map and difficulty, rename the value
To see the maps list write maps * in console (space between maps and *)
Sound
To fix the sound type snd_rebuildaudiocache in console
Change your name
Go to your left4dead installation folder and open rev.ini whit notepad or word
Almost at the end of the text you will find
PlayerName=!DefaultPlayerName!
Type your name after the = save and exit