... MS, Atari, Commodore, PS (Personal System from IBM), Amiga 1000, all copied Apple (first Lisa and later Macintosh). (If you are old enough to remember). In fact the first usable OS MS sold was Windows 3.0 and 3.1 in 1993.
When the Lisa hitted the market in 1984 and Macintosh in the begining of 1985 there were not any Windows.
MS made at the last part of 1985 a graphical shell almost like the DOS-shell but resembling MACintosh that was called Windows 1.0, but only to apear in the scene like Commodore GEOs, Amiga 1000, Atari 520, etc.
In fact Amiga 1000 hitted the market before Windows 1.0 even when in Commodore they had to develop the hardware and the software.