erratic behaviors of CTRL key?

I just got a problem with my keyboard ctrl key, which can be 100% reproduced by following steps:
1. keep the mouse focusing on "my computer" window or "desktop"
2. press either of "ctrl" keys
3. the whole desktop is refreshed once; the taskbar disappears and comes out again; any open window is closed.(It performs like ending and starting the "explore.exe" thread in windows taskmanager.) Weird... can ctrl key do this?

However, if let the mouse focus on other applications, say notepad, firefox and WMP, ctrl key behaves normally.
I guess there might be a missetting or something, any idea? guys

Thanks in advance!

 

Interesting. If I remember correctly, there was an option in the Accessibilities Options to show the cursor at any given time by pressing Ctrl (or Alt, I cannot remember). Maybe something has gone wrong with this feature, that's the only thing that comes to my mind.

 

thanks for advices! I found an option "show location of pointer when I press the ctrl key" under control panel->mouse->pointer options. I have tired to disable/enable it, but, unfortunately, the odd phenomenon still occurs.