Ctrl + Space not working

Been trying to play Half-Life and various other FPSs and notice that the key combination ctrl and space doesn't do anything. No jumping while crouching (or long jumping in HL, making the game impossible) for me!

I know some keyboard manufacturers disable certain key combinations during the manufacturing process for whatever reason, but I've tried different keyboards; this combination works on none of them and I find it hard to believe that five different manufacturers would omit the same key combinations.

How can I fix this problem? (I am running 7, by the way)

i'm suffering from this too, yesterday somehow the ctrl+space stopped working and as a programmer this is a very common combination in various IDE's (content assist)

right now i went around this by making it ctrl+alt+space in eclipse IDE but still it is not comfortable.

I have the answer!!! I had this problem as well. What is happening is that Ctrl+Space switches your language from English to whatever you have set as default. In my case it was Chinese. The switch caused my keys to stop working properly in Half Life 2 and anything else that used the Half Life Source engine. Go to your desktop and in the lower right corner, there should be the letters 'EN' inside a square on your taskbar. Right click it and choose setting. Since I can't read Chinese, I just removed the alternate language so that English was all that was left. I think there is an option just to turn the feature off but this worked for me.

Good luck!