New
#11
You really need to read each description from each seller.
The 3rd link looks like OEM versions which are locked to the first PC you install it on. Also you get only one disk, either 32bit or 64bit.
The Full and Upgrade versions have both 32bit and 64bit disks and can be reinstalled on any system but only one at a time.
The £40 from the 2nd link is just a product key to upgrade from Home ver to Pro ver. Its called Anytime Upgrade. And some of the others are shipped from the US.
Jim