Getting a copy of windows xp

hey everybody,
so, my brother got a virus and crashed the computer. It was a pirated copy of windows and i lost the disc i used to install it. So i'm pretty handy with torrenting programs and getting them to work and all that, and i have a laptop so i can still get on the internet and everything.

 I torrented a copy of xp that all the comments were saying worked. Burned it in powerISO and it said it was bootable. I popped it in my computer, set the cd drive to first boot priority, and ... nothing. It won't boot off the cd. I've tried this with burning it in multiple programs, multiple ways, and i've even downloaded 2 more copies of xp. All to no avail.

So, i've resorted to good ol' newschoolers for some help. Time is kind of an issue, I'm running pretty late on putting out a project for killington.

Thanks a bunch in advance.