DFI Boards: How to use the boot-up hot keys?

I'm talkng about the hot keys that are assigned to CMOS reloaded profiles. Here's a forum post that explains about them. I just don't know when or how I'm supposed to press the given button. Do I hold it? Do I press it repeatedly? Do I press it once? etc.

Good question. I have had three DFI boards and never used the feature...

So I figured it out. It HAS TO BE a PS/2 keyboard, and you hold it during boot up.