I doubt very much if your laptop can boot from a usb stick - may be wrong - but I understood what is downloaded is an iso file which needs to be burnt to cd.
I always recommend that pc users pre-plan for "disasters" and have a recovery toolkit available. This toolkit would contain such things as the Ultimate Boot CD, NTFS4Dos, boot floppy disk, OS cd, and some others, so that when the disaster struck recovery tools would be available immediately. Much like the toolkit in your auto, would you wait for a flat on the freeway before sourcing a spare tire and a wheel wrench?
Anyway, that's just my theory. If you have major problems with downloading/burning the UBCD it is available for purchase very cheap (about US$10-15 delivered). See the link on the UBCD site.
Now I must go to work so will check back with you tomorrow.
Good luck