I doubt if it is possible. It would be a license infringement to move the same copy of Windows from one computer to another and that would definitely be possible with an external install.
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Custom Build
OS
Windows 7 Home Premium 32-Bit - Build 7600 SP1
CPU
Intel Core i3-2120 3.30Ghz
Motherboard
Asus P8Z68-V LX Intel Z68 Socket H2 ATX
Memory
Kingston 4 GB DDR3 1333 mhz
Graphics Card(s)
AMD Radeon HD6670
Sound Card
Sound Blaster Audigy SE 24-Bit
Monitor(s) Displays
Asus VE228
Screen Resolution
1440 X 900
Hard Drives
OCZ Vertex 3 120 GB Sata 3 SSD ==
Kingston SH103/S3 120 G Hyper X 120 GB SSD ==
Western Digital 500 GB Caviar Green 7200 RPM ==
PSU
Corsair CX600M == 600 Watt
Case
NZXT Apollo - Silver with Clear Side Panel
Cooling
Three 120 mm Fans
Keyboard
Microsoft Natural 4000
Mouse
Microsoft Custom Optical 3000
Internet Speed
AT&T Fiber Optic Wireless Network
Antivirus
Microsoft Security Essentials
Browser
Chrome
Other Info
120 mm Blue LED Fan -- Three Blue LED Lazer Light Sticks
i boot my flash memory with View attachment BOOT FLASH.txt or View attachment 246845 But these methods can not boot from my external hard drive.why?
Flash memory is different from the external hard drive?
how Boot an external hard drive?