Abstract: A briefcase adapter for carrying a portable computer in a briefcase comprising a panel for partitioning the briefcase into an upper and a lower compartment and an adjustable frame including a front frame member and a rear frame member held in substantially parallel spaced relationship relative to each other by a pair of side frame members disposed in substantially parallel spaced relationship to each other and disposed in substantially perpendicular relationship to the front frame member and the rear frame member, front and rear frame member adjustment assemblies to selectively and lockably adjust the length of the front and rear frame members for frictionally holding the adjustable frame in place within the briefcase, side frame member adjustment assemblies to selectively and lockably adjust the spacing between the front and rear frame members, and a frame adjustment assembly to selectively and lockably adjust the spacing between the side frame members to selectively adjust the substantially rectangular comp