Quick XP/Ubuntu question

[forrestcupp]

There's nothing that actually combines Windows and Linux. The closest thing you'll get is to run one or the other in a virtual machine.

Wubi allows you to install Ubuntu from within Windows, but you still have to reboot to switch OS's.

But there is an open source ground-up implementation of Windows called ReactOS. I don't think it's actually ready enough to use as a serious OS.