The 3. x and 4. x family includes Windows 3. 0, Windows 3. 1x, Windows 95, Windows 98, and Windows Me.

In this respect the functionality of Windows 95 moved closer to Windows NT, although Windows 95 / 98 / ME did not support more than 512 megabytes of physical RAM without obscure system tweaks.

On 25 June 1998, Microsoft released Windows 98 ( codenamed Memphis ).

USB support in Windows 98 is marketed as a vast improvement over Windows 95.

In 1999, Microsoft released Windows 98 Second Edition, an interim release.

A number of features from Windows 98 were incorporated also, such as an improved Device Manager, Windows Media Player, and a revised DirectX that made it possible for the first time for many modern games to work on the NT kernel.

While Windows 2000 upgrades were available for Windows 95 and Windows 98, it was not intended for home users.

In September 2000, Microsoft introduced Windows Me ( Millennium Edition ), which upgraded Windows 98 with enhanced multimedia and Internet features from Windows 2000.

Windows Me was conceived as a quick one-year project that served as a stopgap release between Windows 98 and Windows XP.

The merging of the Windows NT / 2000 and Windows 95 / 98 / Me lines was finally achieved with Windows XP.

* Windows 2000 or later, CE, Mobile

Then Windows 2000 Server edition, and revised to extend functionality and improve administration in Windows Server 2003.

Operating systems that supported Alpha included OpenVMS ( previously known as OpenVMS AXP ), Tru64 UNIX ( previously known as DEC OSF / 1 AXP and Digital UNIX ), Windows NT ( until 4. 0 SP6 and Windows 2000 RC1 ), GNU / Linux ( Debian GNU / Linux, Gentoo Linux and Red Hat Linux ), BSD UNIX ( NetBSD, OpenBSD and FreeBSD up to 6. x ), as well as the L4Ka :: Pistachio kernel.

A Microsoft Windows ( 2000 or newer ) port was made available starting with the 2. 2. 0 series.

In hindsight, Cairo was a much more difficult project than Microsoft had anticipated and, as a result, NT and Chicago would not be unified until Windows XP — albeit Windows 2000, oriented to business, had already unified most of the system ’ s bolts and gears, it was XP that was sold to home consumers like Windows 95 and came to be viewed as the final unified OS.

This problem plagued the NT line all the way through Windows 2000.

Microsoft released Windows 2000 in February 2000.

Windows 2000 is also the last NT-kernel Windows operating system to lack product activation.

Windows 2000 was available in six editions:

* Windows 2000 Professional

* Windows 2000 Server

* Windows 2000 Advanced Server

* Windows 2000 Datacenter Server

* Windows 2000 Advanced Server Limited Edition

* Windows 2000 Datacenter Server Limited Edition

Windows Me was criticised for stability issues, and for lacking real mode DOS support, to the point of being referred to as the " Mistake Edition " or " Many Errors.

" Windows Me was the last operating system to be based on the Windows 9x ( monolithic ) kernel and MS-DOS.

The aim of WinFLP is to give companies a viable upgrade option for older PCs that are running Windows 95, 98, and Me that will be supported with patches and updates for the next several years.

* Windows Me ( version 4. 9 )

*** Microsoft Windows 9x series ( 95, 98, Windows 98SE, Me )

* 2000 – Microsoft releases Windows Me.

The CD has also been updated, first to run on Windows 95 / 98 using DirectX and later Windows Me / 2000 / XP.

A patch is available for download from Adventure Soft's site, to update older releases to run on Windows Me / 2000 / XP.

* Microsoft Windows contains application compatibility shims to make the platform compatible with most software from earlier 32-bit and 16-bit versions ( e. g. Civilization ( circa 1991, designed for Windows 3. 0 ) running on Windows Vista ).

EFI booting has been supported in only Microsoft Windows versions supporting GPT, the Linux kernel 2. 6. 1 and later, and Mac OS X on Intel-based Macs.

Some apps such as Microsoft Office are available in versions for several different platforms ; others have narrower requirements and are thus called, for example, a Geography application for Windows or an Android application for education or Linux gaming.

As a 16 bit application, the program will not run natively under 64 bit versions of the Windows operating system.

It has undergone numerous revisions for various platforms ( including Windows, Macintosh, Amiga, Atari ST, PlayStation, N-Gage and Super Nintendo ) and now exists in several versions.

Windows includes similar functionality, so the Cygwin library just needed to provide a POSIX-compatible application programming interface ( API ) and properly translate calls and manage private versions of data, such as file descriptors.

For instance, on newer MS Windows computers, the older FAT-type file systems of MS-DOS and old versions of Windows are supported, in addition to the NTFS file system that is the normal file system for recent versions of Windows.

In Microsoft Office 2007 and later versions, Internet Explorer 7 and later versions and Windows Live Messenger, ClearType is also turned on by default, even if it is not enabled throughout the operating system.

Doom became a " killer app " that all capable consoles and operating systems were expected to have, and versions of Doom have subsequently been released for the following systems: DOS, Microsoft Windows, Linux, Apple Macintosh, Super NES, Sega 32X, Sony PlayStation, Game Boy Advance, iOS, Symbian OS, RISC OS, Atari Jaguar, Sega Saturn, Nintendo 64, Tapwave Zodiac, 3DO, Xbox, and Xbox Live Arcade.

For example, EDLIN in early MS-DOS versions and 32-bit versions of Windows NT has a somewhat similar syntax, and text editors in many MUDs ( LPMud and descendants, for example ) use ed-like syntax.

However, Edlin is included in 32-bit versions of Windows NT, since NTVDM's DOS support is based on MS-DOS version 5. 0.

Opera was somewhat faster, but it was proprietary software distributed in trialware and adware versions, both of which lacked some of the functionality of the Microsoft Windows version.

Newer versions of popular browsers such as Google Chrome, Firefox, Opera, and Internet Explorer on Windows Vista implement the Online Certificate Status Protocol ( OCSP ) to verify that this is not the case.

Modern Windows operating system versions are based on the newer Windows NT kernel that was originally intended for OS / 2.

Later, two new versions were released: Windows / 286 2. 1 and Windows / 386 2. 1.