This procedure lets you install Windows from a usb pendrive. Works from Vista/2008 and later
First you need
* Usb pendrive of at least 4GB (Content will be erased)
* Windows installation medium or iso. Windows Vista or later
Prepare usb pendrive
* Insert the pendrive in an available port and copy any data you need to preserve to another locaiton
* Open an elevated commandprompt (“run as administrator”)
* Write “diskpart” and press enter
* Inside diskpart write “list disk” and identify the number for the pendrive.
* Enter the following command, in the example below the pendrive is disk 1 in diskpart.
SELECT DISK 1
CLEAN
CREATE PARTITION PRIMARY
SELECT PARTITION 1
ACTIVE
FORMAT FS=NTFS QUICK
ASSIGN
EXIT
* Copy the content of the Installation medium to the pendrive or extract the iso-file using 7-zip or similar program
Then you should be all set, remember the boot order in BIOS when you want to boot from the pendrive.