Copying a disk is considered a serious crime and you could spend some jail time and have a big fine.
If it were sent through a FTP, it would still be illegal because it is copied. (hence the piracy)
If anything, ask a neighbor for the same installation disk if they have it. Don't ask for a copy of the disk. In fact, thats probably not good advice. Do all you can to avoid breaking the law. In fact, it could be an even better idea to search eBay. That's how I got my disk, new and still sealed in a package.