Use MacBook to create bootable windows xp usb drive

Hello,

I am trying to reformat my old desktop with windows xp pro installed on it, however my cd drive is not working. Is it possible to download xp pro from somewhere? If so, how can I create a bootable usb drive using my macbook pro?
Im not extremely computer savvy so I wanted to make sure Im not going to do anything to my mac before doing something I shouldn't be.

Thanks in advance

 

I would just swap out the DVD drive in the computer, since they are so cheap nowdays. See this regarding using a Pendrive for installing Windows XP Pro http://computernetworkingnotes.com/xp-tips-and-trick/install-xp-form-pen-drive.html

As for downloading an image, you cannot really get it from anywhere. You can go through the process here http://support.microsoft.com/kb/326246/en-gb to get a replacement copy.