how can i intstall windows xp via usb on a laptop which has no cd room

Go here: http://www.komku.org/2008/11/instal... Note: Your computer's BIOS must support USB as a boot device.
Two other ways come to mind. If you want to use a stick, use ImgBurn to capture the XP disk as an ISO and then install it on a multiboot stick with YUMI. Or just buy an external optical drive.
http://liliputing.com/2008/04/insta... Works for machines having USB ports, not just netbooks.
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