Introduced in 1985
System requirements include MS-DOS 2.0, 256KB of RAM, and a hard drive or two floppy drives
Windows 1.0 was a 16 bit graphical operating system. It was Microsoft's first GUI for the PC. The tiling windows were controversial even within the Windows team. Subsequent versions featured overlapping windows, which made better use of small screens.
Introduced in 1992
System requirements include 286 PC with 1MB RAM and hard drive
With version 3, Windows had the features and performance that consumers wanted. Windows 3.1 on an Intel-386 PC became many people's introduction to the graphical user interface.
Introduced in 1995
When millions of new users were just joining the PC revolution, Bob was designed to be user-friendly. Based on two Stanford professors "social interaction" research, the hope was that the system would be so easy it wouldn't require a manual.
Introduced in 2009
System requirements include 1GHz processor, 1GB RAM, 16GB free disk space
Windows 7 featured a 64-bit operating system, which allowed for a lot more RAM. This meant better performance running real-time multimedia applications, including video and 3D games.