It's not all that hard. The tools around now make it fairly easy but don't expect everything to work. Depending on the machine you might have problems with the built in audio or wifi or ethernet but you can get external usb to replace them. As for the trouble? Well, what would you rather use - a lappy a couple of years old with Vista?
or .....
But Dannat's right, looking at a new laptops, it'd be Mac.