improvements in OEM Service Releases OEM Service Releases of Windows 95 introduced support in Windows for several core new technologies which were not included in the original release of Windows 95. These include the Internet Explorer web browser, DriveSpace compression, OpenGL, DirectX, FAT32 file system support, UltraDMA mode for disk drives, Universal Serial Bus, IEEE 1394 (FireWire), and Accelerated Graphics Port. Accessibility features Windows 95 introduced computer accessibility features like Sticky keys, FilterKeys, ToggleKeys, Mouse keys. Microsoft Active Accessibility API was introduced as an add-on for Windows 95. System requirements Official system requirements were an Intel 386DX CPU of any speed, 4 MB of system RAM and 50–55 MB of hard disk space depending on features selected. These minimal claims were made in order to maximize the available market of Windows 3.1 migrations. This configuration would rely heavily on virtual memory and was only optimal for productive use on single-tasking dedicated workstations. It was possible to run Windows 95 on a 386 SX, but this led to even less acceptable performance due to its 16-bit external data bus. To achieve optimal performance, Microsoft recommended an i486 or compatible CPU with at least 8 MB of RAM. Windows 95 may fail to boot on computers with a processor faster than 2.1 GHz and more than approximately 480 MB of memory. In such a case, reducing the file cache size or the size of video memory can help. The theoretical maximum according to Microsoft is 2 GB. Most copies of Windows 95 were on CD-ROM, but a -inch floppy version was also available for older machines. The retail floppy disk version of Windows 95 came on 13 DMF formatted floppy disks, while OSR 2.1 doubled the floppy count to 26. Both versions exclude additional software that the CD-ROM version might have featured. Microsoft Plus! for Windows 95 was also available on floppy disks. Upgradeability Windows 95 was superseded by Windows 98, which also included the Windows Desktop Update and Internet Explorer 4 by default. It could still be directly upgraded by either Windows 2000 Professional or Windows Me. Office 2000 is the last version of Microsoft Office to be compatible with Windows 95. Similarly, Windows Media Player 7.0, released in June 2000, and DirectX 8.0a, released in February 2001, are the last versions of Windows Media Player and DirectX available for Windows 95, respectively. Internet Explorer Windows 95 originally shipped without Internet