DOS-based VDMs appeared with Microsoft's Windows/386 2.01 in September 1987.[13] DOS-based virtual DOS machines were also present in Windows 3.0, 3.1x and Windows for Workgroups 3.1x running in 386 Enhanced Mode as well as in Windows 95, 98, 98 SE and ME. One of the characteristics of these solutions running on top of DOS is that the memory layout shown inside virtual DOS machines are virtual instances of the DOS system and DOS driver configuration run before the multitasker is loaded, and that requests which cannot be handled in protected mode are passed down into the system domain to be executed by the underlying DOS system.