Re: booting and running laptop from usb drive
Sometimes even if you set BIOS to boot USB before internal HD, for safety reasons (virus/worm avoidance) it may still boot the hard drive unless you press a specific key (maybe F12 or Esc) during BIOS splash screen to select boot order. I have noticed that with Dell laptops.
It is even a little more convoluted on my Acer W500P tablet PC, because I have to press and hold Windows button and power button for a few seconds in order to use F2 to get into CMOS setup, or F12 to select boot order (to boot 64-bit 11.10 from internal USB connected SDHC). Without a keyboard attached, it boots internal SSD (Win7) only, because there would be no way to hit F12 during boot.
i5 650 3.2 GHz, 8 GB, nvidia GTX 550 Ti 32" 1080p | i7-4700, 8 GB, Intel HD 4600/nvidia GTX 765M 15.6" 1080p | etc.