Recently i wanted to move my OEM copy of Windows 7 professional to another system as my laptop crashed,but the following were the startling relevelations.
OEM versions of Windows 7 are identical to Full License Retail versions except for the following:
– OEM versions do not offer any free Microsoft direct support from Microsoft support personnel
– OEM licenses are tied to the very first computer you install and activate it on
– OEM versions allow all hardware upgrades except for an upgrade to a different model motherboard
– OEM versions cannot be used to directly upgrade from an older Windows operating system
Some links to read more on the licensing issues.