Windows 95

Microsoft Windows 95 is an operating system with a graphical user interface for personal computers (PC). It was the first operating system of Windows series from Microsoft, which widely supported the 32 -bit operation of the processor, without sacrificing backward compatibility with the then widespread DOS programs. These were (and still are to this day ) only runs under NT systems in a Virtual DOS Machine, which eg direct hardware access that require many of these programs, consistently prevented. Like Windows NT, Windows 95 backward compatible for 16- bit Windows programs.

After its launch on 24 August 1995, Windows evolved 95 to hitherto most successful operating system on the market and founded the Windows 9x series.

  • 2.1 File System
  • 2.2 Graphical User Interface ( GUI) and user guide
  • 2.3 Device support

History of development

February 1995 - Windows 95 is released

In February 1995, a trial version of the hitherto secret Windows 95 was distributed to a handful of people. Previously it was known only as Windows 4.0 or below its working title Windows "Chicago". Everyone who was allowed to participate in the testing stages, had to sign a confidentiality agreement. On August 24, 1995, Microsoft released more numerous tests releases the final version for sale. Their version number was 4.00.950. Microsoft began the biggest product launch of the Group's history.


This Microsoft rang on a broad front, the end of the 16 - bit architecture. In 16 -bit mode, the x86 line, among other DOS and early versions of Windows up to and including running Microsoft Windows 3.1 (Windows 3.1 is partially 32- bit capable ). Windows 95 uses, as well as its direct successor Windows 98 and Windows Me, MS- DOS, which is required to start and for some important system processes and drivers.

It is disputed whether Windows 95 was considered a " graphical user interface for DOS" or as a largely self-contained operating system:

  • It can not work without routines of the " underlying DOS" in some areas.
  • Starting Windows 95 and DOS DOS would stay loaded in the background including all TSRs, as seen to Windows does not differ from a DOS application that switches into protected mode.
  • With 16 -bit applications (Windows 3.x/DOS ) is still not a preemptive multitasking possible.
  • Because of only limited memory protection, a 32 -bit program, the whole system block ( " levered " preemptive multitasking ). Likewise, the running in the background DOS by faulty 16 -bit accesses continue to be paralyzed, which can also be demonstrated by DEBUG.EXE.
  • In important areas of an operating system, it is self-contained and much more modern and more powerful than DOS: Memory management, memory protection, CPU-Zuteilung/Prozess-Scheduler )
  • But only with respect to 32 -bit applications, so do not use the Windows-3.x-/DOS-Kompatibilitätsverhalten.


The official support of Windows 95 with Microsoft updates and fixes ended on 31 December 2001.

Medial Introduction and Start-up tone

In August 1995, Microsoft introduced the product with the largest ever advertising campaign. The introduction of the "Start " button was accompanied in television commercials with the song " Start me Up" by the Rolling Stones.

The music composed specifically for Windows 95 startup melody was created in 1994 by Brian Eno, after he was approached by Mark Malamud and Erik Gavriluk ( senior developer of Microsoft Chicago project). Microsoft wanted a piece of music that is inspiring, universal, optimistic, futuristic, sentimental and emotional, and yet should be other attributes needs. Also, there should be a maximum of 3 ¼ seconds. Eventually, however, were from six seconds.

To both inexperienced computer users as well as older versions of Windows to allow for rapid familiarization with the new interface of the operating system, its operation and the new multimedia possibilities, many pre-installed computers was a CD -Rom entitled Windows 95 Start! at, an interactive computer course.

Technical innovations

According to Microsoft, among others, the following improvements over Windows 3.1 exist:

  • Full 32- bit protected -mode operating system, unlike Windows 3.1 required a separate DOS operating system more
  • Preemptive multitasking and multithreading ( " concurrency " ), improves the reactivity of the operating system and allows programs to operate without problems in the background
  • 32 -bit file systems such as VFAT, CDFS and network redirectors
  • 32- bit device driver for the overall system and thus extended address spaces
  • Robust against bugs and better removal of program code after the end of the faulty program ( through memory protection and centralized storage management )
  • More dynamic system configuration, reduces the need for post configuration for the user

Windows 95, Windows NT 3.1, and 3.5 according to (both with the user interface of Windows 3.x) the first Microsoft operating system, which is based for the most part on the 32- bit architecture ( in the x86 compatible protection mode). IBM OS / 2, which already dominated long periods of time, this technique could not prevail on the market against Windows. Here were combined ( with their specific memory protection ) in a kind of symbiosis of the Microsoft 16- bit DOS, 16 - bit Windows and 32 -bit Windows architectures. Most of the software at the time ran on DOS, which made a consistent Windows NT development unattractive.

With Windows 95 could now also a Win 3.x successor to run multiple programs simultaneously. Previously, programs ( Windows 3.x) wait until the previous program released the processor. Multitasking is indeed already present in previous versions of Windows, but it is still there to co-operative multitasking, so there is only one program always runs at the same time, the others are only kept in memory and as long stopped. The pre-emptive multitasking in 32- bit mode now enables a system- controlled quasi- parallel operation in the time-slice method ( see also Scheduling), but for backward compatibility only with limited memory protection.

The registry database is a central, system-wide unique and competitively accessible space for configuration information was introduced; they solved the system of the initialization of Windows 3.1 almost completely. However, use even today occasionally still use programs configuration files instead of registry entries, especially portable software.

File system

Through the file system extension VFAT, the system allows for the first time the use of longer file names on Windows, so that the well-known DOS limitation attributable to 8 3 characters for the name. Now 255 characters are allowed, but including the path name, which can cause additional problems when copying in subfolders. In this case, Windows is different, although no upper and lower case letters, but retains the title of the document in writing. With VFAT Microsoft wanted the new file system make it compatible to the old, so that each long name nor receives an automatically generated DOS-compatible names, such as " DOCUME ~ 1.DOC " next "Documentation of the new Projekts.doc " (behind the tilde are duplicate names numbered easy). This means that all files created on VFAT also be used by DOS users and users from Windows to version 3.11 (if the underlying file system FAT12 or FAT16 which is supported by DOS, but not FAT32).

Windows 95B introduces support for FAT32, whereby an extended address space is available. The improvement over FAT16 is mainly to support larger disk partitions ( over 2 GB) and in smaller memory sectors, whereby the unused memory is reduced especially for small files.

The online data compression Drive Space from DOS 6.22/DOS 7 is the first time also configurable with a graphical user interface. Together with Microsoft Plus! the effectiveness of this compression was 3 ( the third version ) enhanced by better algorithms ( HiPack and Ultra Pack ) in Drive Space again and also integrated into Windows 95B without additional software into the operating system. The problematic data security and other disadvantages, however, led to the fact that the program lost since the availability of large hard drives at cheap prices fast in importance.

Graphical User Interface ( GUI) and user guide

Extensively are also the innovations in the graphic area, especially the Windows Start menu. Microsoft has created with Windows 95, a user interface that is similar to use as the operating system OS / 2 initially developed in cooperation with IBM The taskbar at the bottom of the screen was new in Windows. When the user clicks on "Start", he will receive a menu where he retrieve the available programs, call the recently used documents, change settings, get help, and turn the computer can was (often cited the strange -looking prompt: "Click Start to finish "). The taskbar (the " Band" in addition to this " start" button ) shows the currently running programs with one click you can switch between them. The old Program Manager from Windows 3.1 was replaced by the so-called desktop, a surface on which appropriate applications associated with symbols ( " links " ) are located. The old program manager was nevertheless included as well as the old file manager in delivery, the appropriate program files are located as " Progman.exe " and " Winfile.exe " in the Windows installation directory. When you install the first Windows 95 operating system (Windows 95A ) could still alternatively select as default interface in the old user even.

The well-known Windows 3.x File Manager has been replaced by the new Windows Explorer. Besides the actual file management he is more responsible for the symbols ( on the desktop ), the windows, the taskbar and some. New for Windows are also the context menu. So you can practically everything click with the right mouse button to see what actions you can perform on each object; then show, for example, differences of possible actions in the context menu between text files and Word documents about. In Windows 3.x, the right mouse button - unlike many application programs, such as WordPerfect - usually without function.

Apart from the file manager ( a holdover from Windows 3.x) Windows 95 is fully Year 2000 compliant. However, for those of Microsoft published an update. In Service Pack 1 (about February / March 1996) is already the nachinstallierbare Internet Explorer version 2.0.

Device Support

In the beta version can use the virtual device driver " CDFS.VXD " (size: 77.2 KB) music CDs are still open like a normal Windows folder. There, the individual songs are shown as copy- WAV files in mono and stereo in three quality levels. A rip music files was therefore not necessary. The " CDFS.VXD " has been in the retail version replaced by only 57.7 KB large file that only displays shortcuts (*. Cda file name). The " CDFS.VXD " of the beta version was functional up to and including Windows ME. It was offered by various computer magazines enclosed CD- ROMs or online for download.

In addition to the also new (and almost unusable because of errors ) USB support, the operating system from the B version also supports AGP graphics cards for the first time.

Windows 95 has always had problems with the ever-growing performance of the hardware. Too fast processors, there was a crash due to a timing error; this error has been since he first appeared at the AMD K6, also called "AMD -K6- Bug". Another error in another system component that has not been resolved by Microsoft, provides a crash if the processor is faster than 2.1 GHz. Also, hard drives that are larger than 32 GB, not supported by Windows 95.


Retrieved from " Windows 95 " four versions were developed, the last of which is divided again into different versions. However, only the first version was commercially available, either as a set of disks, all others were only pre-installed OEM versions and with newly purchased computers and on CD- ROM (not bootable, with additional boot disk ) available.

In DOS, all OSR 2.x versions Report with 4.00.1111. Under Windows without USB support also, they are only the " B" - or " C " entry recognizable.

After Windows 95 should actually Windows 96 (codenamed Nashville ) appear, which, however, was then renamed to Windows 95 B.


For Windows 95 ( original version ) and Windows 95a (OEM Service Release 1 ), the following minimum system requirements:

For Windows 95b and 95c Windows (OEM Service Release 2, 2.1 and 2.5) the following minimum system requirements:


Windows 95 brought not only new, but also problems. The aim of the architecture was, at the same time using the new 32 -bit architecture, full 16 -bit compatibility with Windows 3.11 and DOS, but this was only partly achieved. Also by this compatibility approach gave Windows 95 is far to the stability of the Windows versions of the NT line approach.

By supporting both the old 16 -bit as well as new 32 -bit programs the kernel is significantly more complex than the previous version 3.1x, resulting in significantly lower execution speed of 16 -bit code - especially when screen layout - results. The Windows kernel files access in 16 -bit program code further as under DOS or Windows 3.1 on basic Ein-/Ausgabefunktionen the DOS IO.SYS system kernel.

In the B and C version, there are also some problems with the non- pre-existing USB support, which proved to be error-free. Also some video card drivers refuse under version C their service, but run without difficulty with the older version B.