When the computer's booting it should say something like "Press F12 now to open bios settings" (off the top of my head).Do that.
Some motherboard manufacturers allow you to boot from a device without going into the BIOS and changing the sequence by striking a key and selecting a device.It'll say something like "Press F# for a list of boot devices" or something
It does allow me to hit delete and go to a boot menu and select my flash drive to boot from there, but its annoying manually doing it in the installation process of windows 7.
At least you won't have to spend a minute and a half configuring your boot sequences then go back and reset them.
When im installing windows 7 though, do I boot from the flash drive every time it restarts?
did you get your usb flash drive from any sort of collectors edition for anything that isn't related to memory?