Can I update Windows XP from disk?

How do I transfer official edition of Window XP (disk version) into my USB?

• I currently have Windows XP (the official disk), but it has be several years, and it's probably getting worn out. So I would like to back it up into my USB drive (So that I do not have to buy another disk), so that when I'm reformatting my computer, I don't have to worry about my XP disk not working. Like I said, this is an official version (one that I bought), so that I can get windows update and such. Now, from what I hear, if I were to transfer the disk (by simply "select all" and copy into my USB drive), then the computer will not recognize it as official version. In addition, the ones I find in torrents (even the one that says "cracked" or "official") will mostly not get recognized as official version since they don't get windows updates and such. Simply put, the best way for me to do this is to back up the existing copy of my windows XP in my disc into USB. How do I do that? Can someone please help? (and I need step by step instruction, since I'm not too familiar with computer stuff).

• Answer:

  http://downloadsquad.switched.com/2009/08/27/make-a-bootable-usb-installer-for-windows-xp-vista-7-with-wint/