如何防止Windows XP窃取我的输入Ctrl-Space，这是用于Emacs？

I am learning and using Emacs. What I found annoying is that Ctrl-Space input will be stolen by Windows XP to switch the language bar instead of setting the mark in Emacs. The "language bar" is the native input languages selection such as Chinese keyboard other than English keyboard. Is there a way to temporarily prevent XP from stealing it? I have disabled the language bar from "Regional and language options" from Control Panel but the problem still exists. It doesn't happen on my Windows 2000 desktop at office but it happens on my work Windows XP laptop. Thank you very much.I am learning and using Emacs. What I found ann