To answer the original question, no it isn't possible to RIP XP and rebuild it to run something like Enlightenment. Windows is a closed source binary only software that can not be converted back into the source code. In fact, the code is encrypted. Supersystem files (term used by Microsoft to designate the files used to run the Windows Kernel) are not accessible via the OS, a boot disc, or any other OS for that matter.
I remember a few years ago when a virus was created in Supersystem shell. Luckily, it was caught before it hit the net. If it did, you would never know because the file is so secured by windows, even the file extension is hidden.