Microsoft Windows is a family of operating systems developed by Microsoft since 1983. The latest release is Windows 10.
The hype of 1983
In the early 80s, Microsoft gained popularity for its applications like Word for DOS. But Microsoft was working in something to compete against he Macintosh's friendly user interface. At COMDEX 1983 in November, Microsoft demonstrated a new upcoming product, "Microsoft Windows", running on a personal computer with monochrome graphics, and with various applications running alongside each other in "windows". They really hyped people about it, promising it as the software of the future that will be installed on every PC.
A hard market
After the hype of 1983, they release their product under the name of Windows. But it didn't get the success they expected, as it didn't satisfy the consumer's needs at all. Many people said that it ran slow, or that it used a lot of memory. But despite this, Windows found its place in the market, preparing to grow.
After the excess of hype and a regular market success, Microsoft launched Windows 2 in 1987. This version got significant improvements over its predecessor. Examples of this are overlapping windows and Expanded Memory support.
Windows in the 90s
After Windows 2, Microsoft decided to release a new version of Windows, Windows 3. This release gained popularity and was becoming a defacto standard on many PCs. Here's where Windows started to really grow.
After Microsoft broke its partnership with IBM, they began to develop their own OS. They initially called it NT OS/2, later just NT.
These were the OSes named after a year in the 90s. Thefirst, Windows 95, which gave its massive success to Microsoft, practically monopolizing the market. This lead to a lawsuit in the late 90s/early 2000.