So could you guys make a script with three possible answers: $ ./check-if-my-machine-should-use-686-pae-or-486 Congratulations, you can use the 686-pae kernel! Sorry, you must use the 486 kernel! Maybe: It is hard to say, all we can say is try it. It will either boot or not, and you will know right away. I mean how can this all be so hard to determine algorithmcally?