Fn + F10
Based on this picture: http://skleplaptopy.pl/galeria/n150g1.jpg
That’s the key combination for enabling/disabling the touchpad.
Every laptop/netbook has certain key combinations on its Function keys, usually with a special color (like blue). You use those by pressing Fn together with that one. Assuming yours is like the one on the image I found, it’s Fn + F10.