Sticky Key Sound in Half-Life!

Hi Everyone!

Everytime I play half life( Counterstrike and Dark Messiah) , now and then I hear the sticky key sound. That one "beep" noise. After I hear the beep, I start moving in a single direction because I assume I sticked a movement key (wasd) I have to press the movement buttons to get it back to normal. I went to the control panel and am positive i disabled every check box under the stick key menu. EVERYTHING. Not one box is checked. Sometimes This happens also when i am not playing anything. When I hold down a key, it sometimes beeps. Not often though.
Any help is appreciated!

PS. I don't know if this is the right part of the forum so If mods can move it if its in the wrong section, that would be great.