 System builders further have a different requirement regarding installation media from Direct OEMs.While clean retail media of Windows can be installed and activated on these devices with OEM keys (most commonly using the SLP key that's embedded in to the system firmware already), actual OEM recovery media that was created by the PC manufacturer (not system-builder, nor retail Windows versions) typically only works on the PC model line that was designed for it.So a recovery disc/USB for a Toshiba Satellite P50-B will only work on that model, and not a Satellite S55T.