Заходите в свою КС в директорию cstrike Пример : C:\Program Files\Counter-Strike 1.6\cstrike 

В этой директории найдите файл config.cfg откройте его любым редактором. Данный файл отвечает за настройки игры и нах часто биндят другие команды, если не правельно прописать команду то данная клавиша вообще работать не будет. И чтобы не ходить вокруг до окола удалите в нем все что есть и вставьте следущее :

// This file is overwritten whenever you change your user settings in the game.
// Add custom configurations to the file "userconfig.cfg".

unbindall
bind "TAB" "+showscores"
bind "ENTER" "+attack"
bind "ESCAPE" "escape"
bind "SPACE" "+jump"
bind "'" "+moveup"
bind "+" "sizeup"
bind "," "buyammo1"
bind "-" "sizedown"
bind "." "buyammo2"
bind "/" "+movedown"
bind "0" "slot10"
bind "1" "slot1"
bind "2" "slot2"
bind "3" "slot3"
bind "4" "slot4"
bind "5" "slot5"
bind "6" "slot6"
bind "7" "slot7"
bind "8" "slot8"
bind "9" "slot9"
bind ";" "+mlook"
bind "=" "sizeup"
bind "a" "+moveleft"
bind "b" "buy"
bind "c" "radio3"
bind "d" "+moveright"
bind "e" "+use"
bind "f" "impulse 100"
bind "g" "drop"
bind "h" "+commandmenu"
bind "i" "showbriefing"
bind "j" "cheer"
bind "k" "+voicerecord"
bind "m" "chooseteam"
bind "n" "nightvision"
bind "o" "buyequip"
bind "q" "lastinv"
bind "r" "+reload"
bind "s" "+back"
bind "t" "impulse 201"
bind "u" "messagemode2"
bind "w" "+forward"
bind "x" "radio2"
bind "y" "messagemode"
bind "z" "radio1"
bind "[" "invprev"
bind "]" "invnext"
bind "`" "toggleconsole"
bind "~" "toggleconsole"
bind "UPARROW" "+forward"
bind "DOWNARROW" "+back"
bind "LEFTARROW" "+left"
bind "RIGHTARROW" "+right"
bind "ALT" "+strafe"
bind "CTRL" "+duck"
bind "SHIFT" "+speed"
bind "F1" "autobuy"
bind "F2" "rebuy"
bind "F5" "snapshot"
bind "F6" "save quick"
bind "F7" "load quick"
bind "F10" "quit prompt"
bind "INS" "+klook"
bind "PGDN" "+lookdown"
bind "PGUP" "+lookup"
bind "END" "centerview"
bind "MWHEELDOWN" "invnext"
bind "MWHEELUP" "invprev"
bind "MOUSE1" "+attack"
bind "MOUSE2" "+attack2"
bind "PAUSE" "pause"
voice_modenable "1.000000"
voice_scale "0.750000"
MP3Volume "0.800000"
name "Player"
bottomcolor "6"
topcolor "30"
model "gordon"
rate "2500.000000"
s_eax "0.000000"
s_a3d "0.000000"
volume "0.800000"
hisound "1.000000"
suitvolume "0.250000"
bgmvolume "1.000000"
gamma "2.500000"
brightness "1.000000"
viewsize "120.000000"
sensitivity "2.000000"
d_spriteskip "0.000000"
cl_himodels "0.000000"
console "1.000000"
sv_aim "1.000000"
joystick "0.000000"
m_filter "0.000000"
_windowed_mouse "0.000000"
crosshair "1.000000"
lookspring "0.000000"
m_pitch "0.022000"
lookstrafe "0.000000"
+jlook
+mlook
cl_timeout 300
hud_fastswitch 1
exec userconfig.cfg

Теперь сохраняйте и играйте.