What have you downloaded? Assuming it's an ISO file.... you just need to burn a CD/DVD with the image, so you can boot from it.
http

/www.makeuseof.com/tag/make-bootable-usb-cd-dvd-install-windows-using-iso-file/
Near the end, it covers off disks.
Then, once complete - put it in the M5's disk drive and it should run.
Then, direct the install location to the harddrive (assuming there's on in there??) and let it do it's thing.