Windows '95 is currently the second most popular variant of MS-Windows. It was designed to be the replacement Windows 3.1 but has not yet done so completely partly because of suspected security problems but even more because it is not as lightweight and will not work on all the machines that Windows 3.1 will. It is more capable than Windows 3.1 though and now has excellent driver support and more games available for it than any other platform. It is made to run on top of MS-DOS and will not do much of anything if MS-DOS is not on the system. It is thus not strictly an OS per se, but nor is it a true window manager either; rather the combination of MS-DOS and Windows '95 result in a full OS with GUI. It is partially multitasking but has a much greater chance of crashing than Windows NT does (or probably even Mac OS) if faced with a buggy program. Windows '95 runs only on x86 based machines. Currently Windows '95 has several Y2K issues, some of which have patches that can be downloaded for free, and some of which do not yet have fixes at all.