Re: Windows xp
Not all sources of download are illegal...
If you were able to purchase Windows XP from Microsofts MSDN library (not sure what all you need to sign up for...) then there are downloads available there.
If you're simply looking to reinstall Windows XP on an old machine, then there's no risk in borrowing a friends copy as long as you have a key that belongs to you and it is of the same version.
Humans are the only creatures that won't live up to the their potential. Give everything your all. When you die, die on E.
So I ask you, what do you intend to do now?