Windows NT, Windows 2000, and Windows ME
these are an examples of operating system - Windows - Linux - Unix - Mac OS
Windows, Linux, Mac OSX are currently the three most popular computer operating systems. Other operating systems are Solaris, BeOS, Google Chromium os, and many more.
The top three operating systems in terms of market share are Windows, Mac OS X, and Linux.
Mac OS X, Linux, and Microsoft Windows are three types of operating systems. Single-user, multi-tasking, multi-user, and real-time operating systems, or RTOS, are different types of operating systems that computers use.
OpenTTD can currently be installed and played on three main operating systems. These operating systems are Windows (XP, Vista, and 7), Mac OS X, and Linux.
Appleshare,Microsoft Windows server and Novell netware
windows 2003 windows 2008(latest) unix, linux, by rajkumar from udumalpet.
Microsoft Windows, Mac OS X, and Linux
word star - linux framework - solaris access - windows
Essentially there are three that Microsoft still makes available for general home use: Windows 7, Windows Vista and Windows XP.
There are loads more than three - most are designed for a specific purpose, especially for safety critical applications. Three are: Windows Linux Solaris Type in Operating Systems to wikipedia. Why don't people check wikipedia before asking silly questions like this?
only Dos-based operating systems use dot-three file extensions