On June 25, 1998, Microsoft launched the sale of Windows 98 (code name Memphis). which was widely perceived as a slightly improved Windows 95, but most often proved to be more stable and robust than its predecessor three years ago. It included new device drivers and support for the FAT32 file system, which allowed for disk partitions above 2 GB. The support for USB devices in Windows 98 also greatly exceeded the quality of the residual OEM version of Windows 95. A controversial move was the integration of Internet Explorer with the user interface and the system's file manager. which was the reason for the "United States versus Microsoft" court case to determine whether Microsoft was using its dominant position on the PC market to promote its own products of other categories.
In 1999, Microsoft released the second edition of the system, Windows 98 Second Edition, which was a transitional version, and its most important feature was the introduction of the "Internet connection sharing" solution (a trade name given by Microsoft to some form of network address translation), which allowed several computers operating in a local network to share a single Internet connection. Thanks to improved drivers, the operation of the devices was much more efficient. Microsoft also found and fixed bugs in the second edition of Windows 98. According to many sources, the second edition of Windows 98 was the most stable edition based on the kernel of the 9x series.