How can I reload Windows XP Professional on to a Dell latitude X 300 laptop computer without a disk drive?

Windows will not start on my Dell laptop computer, it say's unmountable-boot-volume. I was told to reload windows to see if that would solve the problem. My problem is I have no idea how to reload windows, could someone please give me an idea on how I can do this? Thanks!|||You can download or make a copy of xp and put it on a flash drive. Then boot up the dell laptop with the flash drive in there and reload windows. If you have a legit key you can download a illegal copy of xp just to use it to get your laptop working then use the key you got to genuine the software. Also you might want to go into BIOS and set your usb drive as the first in your boot order so that your laptop will boot from the flash drive when you turn it on.