1. Copy crysis2(5620)_01_03 folder to Program Files(x86) and rename folder to Crysis2
2. If you have 64bit windows, go to Bin64 subfolder, if you have 32bit, go to Bin32 folder
3. Run TEST_BAND.Bat and wait till it finishes then run TEST_CLIENT.Bat and do the same
4. Go back to Crysis2 root folder and open system.cfg in notepad (in admin mode) and replace contents with:

    ; crysis2

    sys_game_folder=GameCrysis2
    sys_dll_game=CryGameCrysis2.dll
    sys_user_folder=Crysis2

    r_ShadersRemoteCompiler=0 ; 0 means local shader compiling
    r_displayInfo = 0 ; disable info at top right of screen
    r_enableAltTab = 0 ; disable alt-tabbing, since it crashes the beta anyway

    log_Verbosity = 1 ; only log errors
    log_WriteToFile = 0 ; don't write log to file
    sys_languages = "english,french,spanish,german,turkish"
    sys_float_exceptions = 0 ; disable performance expensive float exceptions

    net_inactivitytimeout = 32 ; nr. of sec until server trows inactive connection away (was set ridiculously high)
    net_inactivitytimeoutDevmode = 32 ; same as above, but for Devmode (don't know why you'd want to play multiplayer in Devmode?)

    g_enableInitialLoginScreen = 0 ; disable login screen at game startup
    g_gamespy_loginUI = 0 ; disable multiplayer login screen
    net_lanbrowser = 1 ; find LAN (local) matches instead of internet matches in multiplayer serverbrowser
    net_initLobbyServiceToLan = 1 ; make LAN (local) lobbies instead of internet lobbies in multiplayer
    sv_lanonly = 1 ; launch LAN only server
    sv_servername = "LAN" ; server name (should show up in LAN serverbrowser)
    sv_gs_report = 0 ; don't report to gamespy
    sv_gs_trackstats = 0 ; don't send stats to gamespy
    sv_cheatprotection = 1 ; we don't want to cheat now do we

    s_SpeakerConfig = 2 ; 2 is stereo config, seems to provide more consistent quality compared to surround
    s_FormatType = 3 ; 24 bit sample rate sound
    cl_fov = 75 ; larger Field of View, not sure if it works properly
    pl_movement.power_sprint_targetFov = 65 ; increased field of view when sprinting
    r_DrawNearFoV = 75 ; draw near objects in our newly increases field of view

    cl_nickname = "NICKNAME" ; nickname for multiplayer (might not work, in that case, type name NICKNAME in console ingame)

    i_mouse_smooth = 30 ; disable mouse smoothing completely (0 should disable smoothing, but doesn't entirely)

    g_dlcPurchaseOverwrite = 1 ; "Cheat to unlock DLC content on PC without purchase" -Crytek
    g_ignoreDLCRequirements = 1 ; shows servers in browser that run DLC you don't have
    g_presaleUnlock = 0 ; 1 unlocks presale content without voucher
    g_skipIntro = 1 ; skips all intro movies
    g_useOnlineServiceForDedicated = 0 ; dedicated server in LAN mode (don't know for sure, this config crashes dedicated server anyway)

5. Change cl_nickname = "NICKNAME" to contain your nickname
6. Make any other settings tweaks you want, save system.cfg
7. Go back to the appropriate bin folder (Bin64 or Bin32) and run Crysis2.exe