How can I install an OS , like XP , in a Subnotebook ( a small notebook, which doesnt have a CD-rom driver ! )?

I am planning to buy a small notebook , so I can take it with me easily to the Uni lesseons, but I have already the XP OS , and want to change the Original OS in the Laptop into Xp , but it doesnt have a CD driver ! how can I install the new OS ?How can I install an OS , like XP , in a Subnotebook ( a small notebook, which doesnt have a CD-rom driver ! )?
Buy an external CD/DVD drive.



If you want to change the original OS on a laptop be warn that you will void the warranty. The manufacturer will charge a big price to fix the laptop when if stops working.How can I install an OS , like XP , in a Subnotebook ( a small notebook, which doesnt have a CD-rom driver ! )?
If you have a current computer that has the system you want then go into the files in the hardrive and copy them to a USB if you can't fit them all keep deleting the files after they are on the laptop