Why was windows 1.0 considered an operating environment rather than an operating system?

Windows 1.0 was a personal computer operating environment developed by Microsoft. This was considered an environment because it consisted of a multi-tasking shell, with an MS-DOS installation. Therefore, it could run programs designed for Windows, as well as MS-DOS software. Windows 1.0 was not initially well-received because of its heavy reliance on the mouse. However, it is now considered a crucial step for Microsoft.

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