Windows 3.0, the predecessor of 3.1, was released in 1990, and is considered to be the first version of Windows to receive critical acclaim. Windows 3.0 received around 10 million sales before the release of Windows 3.1 on April 6, 1992. Microsoft began a television advertising campaign for the first time on March 1, 1992. The advertisements, developed by Ogilvy & Mather, were designed to introduce a broader audience to Windows.

Windows 3.1 was codenamed Janus. Like its predecessors, the operating environment runs as a shell on top of MS-DOS, although it does not include the MS-DOS Executive shell. After the introduction of Windows 1.0, Microsoft had worked on gaining support from companies to expand its operating environment on different types of PCs. Tandy Corporation was open to shipping Tandy Sensation PCs with the Windows 3.1 operating environment. IBM and its PCs were also provided with Windows 3.1.

Further enhancements were introduced in Windows 3.1. The TrueType font system was introduced to provide scalable fonts to Windows applications, without having to resort on using third-party technology such as Adobe Type Manager (ATM). Windows 3.1 introduced Arial, Courier New, and Times New Roman fonts, in regular, bold, italic, and bold-italic versions, which could be scaled to any size and rotated, depending on the application.

To improve user interaction, Microsoft initiated warning and event sounds, and introduced computer command shortcuts for copy, cut, and paste. Windows 3.1 is also noted for its improvement of multimedia; screensavers, Windows Media Player, and Sound Recorder were introduced into the operating environment. These features were already present on the Windows 3.0 with Multimedia Extensions version, although they were only available to users with newly bought PCs. The Media Player could play MIDI music files and AVI video files, while the Sound Recorder could play, record, and edit sound files that were affiliated with the WAV format.  Minesweeper was officially introduced in Windows 3.1 as a replacement for Reversi, alongside Solitaire. MS-DOS programs were previously not able to be controlled with a mouse; this ended up being introduced in Windows 3.1. Object Linking and Embedding (OLE) was added to allow drag-and-drop embedding of images and formatted text between Windows programs. SVGA color support was also introduced in this version.

File Manager had also received tweaks; split view-mode was introduced, users were now able to browse files without having to open separate windows, while files were able to be dragged and dropped to other locations on the system. An option for quick formatting was introduced to format floppy disks and copy its files without having to quit Windows. File Manager is an MDI application that is used for moving, deleting, and managing files on the system. Microsoft also built Microsoft Bob, a utility that would act as a search assistant, on Windows 3.1, only for it to be released on Windows 95 in 1995. The introduction of Windows Registry, a centralized database that could store configuration information and settings for various operating systems components and applications, also occurred in this version. The Control Panel also received changes; its items were now hard-coded, and additional items could be added by placing additional .cpl files. Similarly, the Calendar uses the .cal extension. Printer management tasks were moved over to Control Panel and Print Manager. Several printer drivers were improved in Windows 3.1, making the Print Manager more efficient to use.  Windows 3.1 also includes troubleshooting and diagnostic tools such as the Dr. Watson utility which saves information about application errors, and Microsoft Diagnostics.

Windows 3.1 also includes add-ons; Video for Windows was introduced in November 1992 as a reaction to Apple's QuickTime technology. At the price of $200, the software included editing and encoding programs. It was later built into Windows 95. Microsoft also published Windows for Pen Computing, a pen computing interface which was created in response to PenPoint OS by GO Corporation. The operating environment was also given limited compatibility with the then-new 32-bit Windows API, by introducing Win32s, an enabling technology. Microsoft also provided WinG, an application program interface, to entice developers to move from DOS to Windows. It also provided a device-independent interface to graphics and printer hardware, and allowed programs to have both read and write capabilities to the WinGDC.

Unlike all previous versions, Windows 3.1 could not run in real mode and it insisted on the use of 80286 processors or above. Because of this, the maximum memory available was increased. While Windows 3.0 was limited to 16 MB maximum memory, Windows 3.1 could access a theoretical 4 GB in the 386 enhanced mode. The actual practical ceiling is 256 MB. Like its predecessors, it runs as a 16-bit system; Windows 3.1 is also the last Windows to run in 16-bit mode. It is also the first Windows to be distributed on a CD-ROM. The setup interface was simplified; express mode was introduced to automatically set up Windows. Windows 3.1 also includes an online tutorial applet for users regarding the use of the Windows 3.1 user interface. In addition it supported the Advanced Power Management standard.

A special version named "Windows 3.1 for Central and Eastern Europe" introduced eleven languages to Windows 3.1. It also provided support for the Cyrillic script. To use Czech, Hungarian, and Polish terminologies this version was required, while to use Russian terminologies a Russian version of Windows 3.1 was needed. Similarly, Microsoft also released Windows 3.1J with support for Japanese, which shipped 1.46 million copies in its first year on the market (1993) in Japan.

Modular Windows was built for real-time consumer electronics, and was designed to be controlled via television. It was a special version of Windows 3.1, which was designed to run on Tandy Video Information System; it allowed users to run multimedia software without having to buy a personal computer. It also contained a software development kit (SDK) for programmers to write applications that would run on devices that have Modular Windows. The SDK was sold for $99. Modular Windows was discontinued in 1994.

Released on November 8, 1993, Windows 3.11 was introduced with fixes for network problems which were present on Windows 3.1 As a minor update, new features were not present in this version. It also did not run on IBM's OS/2 for Windows. Windows 3.11 allowed users to connect to each other as peers to share the resources of their computers. Microsoft replaced all retail and OEM versions of Windows 3.1 with Windows 3.11 and provided a free upgrade to anyone who owned Windows 3.1.

An updated Simplified Chinese version of Windows 3.1 was released in November 1993, as Windows 3.2. The update was limited to this language version, as it only fixed issues related to the complex input system for the Simplified Chinese language. A font editor is present in Windows 3.2; it is used to add new Chinese characters to the already-existing fonts.

Windows for Workgroups served as an update to Windows 3.1, and it was the first version of Windows that was suitable for integrated networking. Initially developed as an add-on for Windows 3.0, it was later released in 1992. It introduced drivers and protocols for peer-to-peer networking. Windows for Workgroups was mostly oriented towards businesses. The two vesion released are:

• Windows for Workgroups 3.11

  The first version of Windows for Workgroups, 3.1, was released on October 27, 1992. Codenamed Winball and Sparta, it allows users to share files, use print servers, and chat online; files could be accessed from other machines that run either Windows or DOS. The Microsoft Hearts card game was also added, while Object Linking and Embedding, which was implemented in Windows 3.1, was also included in the Windows for Workgroups version. The Workgroups version also introduced the Microsoft Mail program, which allowed users to receive and send emails, and Microsoft Schedule+, a time management app.

  Windows for Workgroups could also be accessed from an OS/2 client that uses the Server Message Block (SMB), a protocol used for sharing files and printers over local networks. It introduced support for the NetBEUI protocol. The price sat at $69 for Windows 3.1 users.

• Windows for Workgroups 3.11

  The other version, Windows for Workgroups 3.11, was released on November 8, 1993. It was codenamed Snowball, and it introduced support for 32-bit file access, drive sharing, and group calendaring. It also has built-in fax capabilities.

  It received network improvements; a Winsock package was released for Windows for Workgroups, although it was later replaced by a 32-bit stack add-on package (codenamed Wolverine) that provided TCP/IP support in Windows for Workgroups 3.11. Its connectivity with NetWare networks was increased, while it also introduced support for Open Data-Link Interface cards and Internetwork Packet Exchange drivers. Remote access service was introduced as a product for users to remotely access Windows NT and its Advanced Server networks.

  It runs in 80386 enhanced mode, and it supports the use of network redirectors. It was sold in two versions; the complete package cost $219 while the "Workgroup Add-on for Windows" cost $69.

Windows 3.1 changed some icons, of which the most notable change is the addition of color to icons. Some icons changed include the ones for File Manager, Control Panel, Paint, Notepad and Calculator.

Windows 3.1 introduced TrueType font support, therefore making fonts clearer at any size. They were vector fonts, which meant that they used mathematical equations to define the size of every letter, so they could be scaled to any size without losing quality. Before TrueType fonts, bitmap fonts were used which were made on a grid of pixels, causing them to become jagged and / or pixelated on increasing their size.

Many features from the Mutimedia Extensions pack for Windows 3.0 were integrated into Windows 3.1. One of those programs was Media Player, which could play WAV and MIDI audio files and AVI video files. Sound Recorder was also added, allowing users to record and edit audio files.