Windows XP Download help?

So my little brother messed up our other computer and now we need to reinstall Windows XP. The disc that came with my computer will not work with his, and we have a copy of an XP setup CD that refuses to install on his computer as well. What can we do? I found out I can download it on Ares, but you never know if it's truly the program until you download it. However, it seems pretty legit. It shows me that at least 23 uses have it that are online currently and it's 140.78 mb. So do you think I should give it a shot or would it mess up my computer? Also how would I get it on a disc since it's such a huge file? Wouldn't I have to open the .exe then install it and put it on the disc or could i just put the .exe directly on the disc, but I'm guessing that wouldn't work to install on the other computer.