Actually, VB3 works perfectly well under all 32-bit versions of Windows up through XP; it breaks at Windows 7 (and presumably Vista). Under all the NT-based versions (NT, 2000, and XP), Windows launches a virtual machine call NTVDM.EXE (NT Virtual DOS Machine), upon which runs yet another emulator WOW.EXE (Windows on Windows). This latter emulator presents the non-preemptive message-passing architecture of Windows 3.1 to all the 16-bit Windows applications (like VB3) that run upon it. This actually worked remarkably well; I?ve personally supported an application for 20 years that is written in VB3, including adding new features all that time ? even a Web server! There was also a technique that allowed calling 32-bit DLLs from the 16-bit application. There were a couple of bugs, of course, but generally it was a very stable solution to supporting legacy code. There was even a work-around to NT?s rigorous defense of direct hardware access which continued to work through XP. Windows 7 broke all that. (Presumably Vista actually did, but I?ve never seen a Vista system in the wild...) ~~ Mark Moulding