OK, I just tried it here and the instructions from the TechNet article work perfectly with no changes required. There is no need to run bootsect.
I used a 4 GB USB flash drive, ran the diskpart commands as shown, then copied the contents of the Windows 7 Ultimate RTM x64 DVD to the flash drive. I restarted, pressed F12 for the boot menu on my system (Acer), and chose the flash drive from the menu. It booted the pre-install environment, I chose "Repair your computer", selected my Windows 7 install from the recovery options and launched the command prompt. It works!
Dennis Chung, author of the TechNet article, answers this very question here in the TechNet forum. The question is asked by poster Steve456 and is answered on the second page. There is one exception that Dennis notes when the USB is used as "permanent".