Windows Ver.3.0

Before Windows 3.0, Microsoft had a partnership with IBM, where the latter had sold personal computers running on the former's MS-DOS since 1981. Microsoft had made previous attempts to develop a successful operating environment called Windows, and IBM declined to include the project in its computers. As MS-DOS was entering its fifth iteration, IBM demanded a version of DOS that could run in protected mode, which would allow it to execute multiple programs at once. MS-DOS was originally designed to run in real mode and thus only one program at a time, due to the limited memory of the Intel 8088 microprocessor. Intel had later released the Intel 80286, which had enough memory to perform such multitasking. The two developed the next generation of DOS, OS/2. OS/2 software was not compatible with DOS, giving IBM an advantage.

As the rest of the Microsoft team moved on to the OS/2 project, David Weise, a member of the Windows development team and a critic of IBM, believed that he could restart the Windows project. Microsoft needed a debugging program that could run in protected mode, so it hired Murray Sargent, a physics professor from the University of Arizona whose own debugging program could emulate applications in protected mode. Windows 3.0 originated in 1988 as an independent project by Weise and Sargent, who used the latter's debugger to find problems with Windows. They cobbled together a rough prototype that contained three applications: Microsoft Word, Microsoft Excel, and PowerPoint. They then presented it to company executives, who were impressed enough to approve it as an official project. When IBM learned of Microsoft's upcoming project, their relationship was damaged, but Microsoft asserted that it would cancel Windows after its launch and that it would continue to develop OS/2.

Windows 3.0 was formally and officially announced on May 22, 1990, in the New York City Center Theater, where Microsoft released it worldwide. The event had 6,000 attendees, and it was broadcast live in the Microsoft social fairs of seven other North American cities and twelve major cities outside. It cost Microsoft US$3 million to host the festivities—something its founder, Bill Gates, referred to as the "most extravagant, extensive, and expensive software introduction ever." Microsoft decided not to offer free runtime licenses of the software to applications vendors, as runtime versions of Windows lacked the capacity to multitask. Instead, the company offered upgrades for both full and runtime previous versions of Windows at a cost of US$50 — considerably lower than the full license's suggested retail price of $149. The software could also be obtained by purchasing computers with it preinstalled from hardware manufacturers. The first of these manufacturers were Zenith Data Systems, Austin Computer Systems and CompuAdd, followed by more than 25 others; notably, IBM was not one of them.

Microsoft had intended to make Windows 3.0 appealing to the public in general. The company's Entry Team, assigned to that task, was concerned that the public might perceive it to be no more than a tool for large enterprises, due to the software's high system requirements. Major game publishers did not see it as a potential game platform, instead sticking to DOS. Microsoft's product manager Bruce Ryan compiled games that the Windows team had designed in its spare time to create Microsoft Entertainment Pack, which included Tetris and Minesweeper. There was little budget put in the project, and none of that was spent on quality testing. Nevertheless, the Entertainment Pack was sold as a separate product, and it became so popular that it was followed by three other Entertainment Packs.

On December 31, 2001, Microsoft dropped support for Windows 3.0, along with previous versions of Windows and Windows 95, Windows for Workgroups, and MS-DOS versions up to 6.22.

Windows 3.0 is also considered the first Windows to see commercial success. At the time of release, of the 40 million personal computers installed, only five percent used either previous version of Windows, but within its first week of availability, it rose as the top-selling business software. After six months, two million licenses were sold. Its success was interdependent with the PC industry, exemplified by an explosion of demand for and subsequent production of Intel's more powerful microprocessor, the 80486. Windows became so widely used in businesses that Brian Livingston of InfoWorld wrote in October 1991 that "a company with no PCs that run Windows is almost like a company without a fax machine." Microsoft had spent a total of $10 million in its marketing campaign for the software, including the $3 million for its release.