Atleast, on my and a few of my friends' PCs, when I press and hold all the arrow keys together on Windows 7 and the System sounds are on in the mixer, a beep sound starts playing until I release the keys. On experimenting, I found the following key combinations do the same:
1) Top, Left, Bottom (without right)
2) Home, End, PageUp
3) A few others that I can't remember right now. They have something to with Ctrl and Shift keys.
So I just want to know by curiosity, why does this happen. Can I change the sound as per my needs? Or do some fun stuff with it?
System Info:
Dual booting Ubuntu 12.04 and Windows 7 (Currently on ubuntu so can't check those other keys). 2GB RAM. Sound Card-Realtek AC'97 Audio.