Windows 98 (codenamed Memphis and formerly known as Windows 97) is a graphical operating system released on June 25, 1998 by Microsoft and the successor to Windows 95. Like its predecessor, it is a hybrid 16-bit/32-bit monolithic product based on MS-DOS.
The first edition of Windows 98 is designated by the internal version number 4.10.1998, or 4.10.1998A if it has been updated with the Security CD from Microsoft. Windows 98 Second Edition is designated by the internal version number 4.10.2222A, or 4.10.2222B if it has been updated with the Security CD from Microsoft. The successor to Windows 98 is Windows Me.

Windows 98 Second Edition
Windows 98 was the first operating system to use Windows Driver Model (WDM). This fact was not well published when Windows 98 was released and most hardware producers continued to develop drivers for the older driver standard, VxD. This resulted in the misconception that Windows 98 can use only VxD drivers. The WDM standard spread years after its release, mostly through Windows 2000 and Windows XP, because these systems are not compatible with the older VxD standard. Today, even if hardware producers are not developing drivers optimized for Windows 98, the drivers written to WDM standards are compatible with Windows 98–based systems.

New driver standards

• Upgrading from Windows 95 (FAT16) or 3.1 (FAT): 140-400 MB (typically 205 MB).


• New installation (FAT32): 190-305 MB (typically 210 MB).


• Note: Both Windows 98 and Windows 98 SE can have significant problems associated with hard drives that are over 32 Gigabytes (GB) in size. This issue only occurs with certain Phoenix BIOS settings. A software update has been made available to fix this shortcoming. System requirements
  The release of Windows 98 was preceded by a notable press demonstration at Comdex in April 1998. Microsoft CEO Bill Gates was highlighting the operating system's ease of use and enhanced support for Plug and Play (PnP). However, when program manager Chris Capossela plugged in a scanner and attempted to install it, the operating system crashed, showing a BSOD. Bill Gates said that "that must be why we're not shipping Windows 98 yet." Video footage of this event became a popular Internet phenomenon.
  
  
  Press demonstration
  
  Advantages and disadvantages
  Windows 98 is a hybrid 16/32-bit operating system. It has quite low system requirements; therefore it can gain full potential even on older machines.
  The graphical user interface (GUI) runs on a DOS-based layer. This is partially an advantage and disadvantage. DOS has some limits (such as the number of disk buffers or simultaneously opened files), but through its environment memory managers, drivers or other applications can be loaded which can improve overall system performance and functionality.
  Windows 98 also offers full support for DOS applications in the form of being able to boot in "DOS Mode" (MS-DOS can be booted without booting Windows or putting the CPU in protected mode). This differs from the emulation used in Windows NT-based operating systems in that the latter cannot handle devices such as modem or LAN cards which are required for some DOS applications.
  Since DOS programs provide their own device drivers, some DOS programs, such as those that require a Sound Blaster compatible sound card, cannot run on newer computers without Windows (which provides Sound Blaster emulation in some sound card drivers).
  LAN cards that are not NE2000 compatible generally cannot be used at all by DOS programs, with or without Windows.
  DOS Mode also offers the ability to fix certain system errors without entering the GUI. For example, if a virus is active in GUI mode it can often be safely removed in DOS mode, by deleting its executable files, which usually cannot run without Windows.
  While in "DOS Mode", the 32-bit Windows layer can be started with the same DOS command that was used for older versions of Windows going back to Windows 1.0: WIN.COM
  The biggest advantage of this operating system is its compatibility with older versions of Windows and MS-DOS. It can successfully run very old applications that were written for Windows 3.0, while also being able to run new applications and applications written for Windows NT.
  Another advantage is its small size in comparison to newer Microsoft operating systems. While newer Microsoft OS take up several GB of disk space, Windows 98 can be installed requiring less than 250 MB of HDD space, offering more room for applications and files. It also has a very small memory footprint, so it doesn't reduce the overall system performance the way current OS do on older systems. When installed on newer systems, Windows 98SE can boot within 15 seconds and shut down within 3 seconds, giving it a huge advantage in speed when comparing it to current versions of Windows.
  Legacy support (1994 – release date) is excellent. For example, Windows 98SE may have a driver for 3Com network card made in 1995, but later versions such as Windows 2000 and XP would neither natively support that card nor be compatible with the VxD driver. However, earlier versions of NT may have drivers for these cards (especially considering that NT 4.0 was released in 1996) and these drivers can be used with Windows 2000 and XP. However NT back then did not support as much hardware as it does now. This is one of the greatest advantages of DOS-based operating systems such as Windows 95 and 98 SE.
  Also because now most viruses are written for Windows 2000/XP, it is more likely that a Windows 2000/XP system is infected with a virus than a Windows 98 system.
  
  Disadvantages
  
  ScanDisk - Well known program used to maintain the file system. It offers a DOS and a GUI version. Used to check the integrity of the file system and files stored within.
  Disk Defragmenter - Used to counter the negative effects of filesystem fragmentation. It collects fragmented file parts, reconnects them and rearranges all files in optimal order, thus speeding up file access and allowing faster boot times. Note that Microsoft changed the utility shipping with Windows 2000 and XP, which operates faster than the previously used program but can destroy data when partitioning hard disk drives. This happens as, contrary to the old program, the new defragmenter doesn't necessarily put all files on the same sectors, resulting in the deletion of files when a used drive is partitioned.
  Scanreg - Used to restore the System registry. It tests the registry's integrity and saves a backup copy each time. The maximum amount of copies is eight. Due to a bug the oldest registry copy available cannot be restored (before restoration, the current configuration is backed up and it erases the oldest registry backup listed). The restoration of a faulty registry can only be done in DOS mode. Important DOS commands: scanreg/opt - optimizes the registry by deleting dead entries; scanreg/fix - repairs registry settings.
  Msconfig - A system utility used to disable programs and services which are not required to run the computer. It is a very efficient tool that can multiply the system's stability and speed.
  Sysedit - A system utility used to modify system configuration files in a text window.
  Regedit - Allows manual editing of the registry. Windows 98 System tools
  
  Expanding modules
  Microsoft planned to discontinue its support for Windows 98 on January 16, 2004. However, due to the continued popularity of the operating system (27% of Google's pageviews were on Windows 98 systems during October-November, 2003),