Sounds like you activated the 10-key number keypad. When you hold the function key down, it reverts to the normal keyboard. In effect, you have changed the keyboards default settings to numbers. I don’t happen to have a Gateway laptop, so I don’t know how to change it back, but I’m fairly certain that’s what has happened.
Yeah, that’s it. Either RTFM, or check your function keys around F5 for one that also has a little grid that might look like the number pad on a full 101 board if you squint. Hit Fn-F(Whatever-That-Key-Was) and things are back to normal.
Gateway keyboards used to have another interesting trick: there was a key that, once you pressed it, would let you remap keys (first keypress = key to be remapped; second keypress = key to map the first one to) until you want back and pressed the remap-function key again to tell it you were done. (Don’t ask me whose brilliant idea this was!)