I wanted to do a completely clean install, wiping all the partitions, for my Windows 8 installation on my Build Slate (tablet) PC. I used the Windows 7 USB DVD Download Tool to prep a USB stick but I could not get the slate to boot from it. Some googling, and I found the reason why.
The UEFI BIOS will not boot from an NTFS formatted USB stick. Doh! I followed the instructions on the above post to prep a new USB stick to install Windows 8, and successfully got the install from USB to start up.