HP L77266-001 base enclosure is the bottom cover for the HP ProBook 450 G7 with discrete graphics. It provides the lower casing component for this specific laptop configuration and is identified in HP’s service parts guide by its exact part number.
This part is designated for discrete-graphics models. HP lists L79384-001 separately for ProBook 450 G7 models with UMA graphics, so the two part numbers represent different configuration variants. The service guide describes the cover as removable for servicing and specifies loosening its five captive Phillips screws during removal.