by Alex Free

Open95Keygen is a portable open source program that generates random valid Product Keys (both OEM and Retail types) for Microsoft’s Windows 95 and Windows NT 4.0 operating systems.

The Windows 95/NT 4.0 OEM/Retail Product Key algorithms have been reverse engineered by many people. Open95Keygen is a clean room design implementation not based on any existing software, it is written based on the specifications of the algorithm which is inherently not copyright infringement. I was inspired to write Open95Keygen after watching the YouTuber stack smashing’s video Why 111-1111111 is a valid Windows 95 key.

Table Of Contents


Version 1.0.2 (2/16/2023)

open95keygen-1.0.2-windows_x86 For Windows 95 OSR 2.5 Or Newer (32-bit Windows)

open95keygen-1.0.2-windows_x86_64 For 64 bit Windows

open95keygen-1.0.2-linux_x86 For modern x86 Linux distros

open95keygen-1.0.2-linux_x86_64 For modern x86_64 Linux distros

Source Code


Version 1.0.1 (2/13/2023)

open95keygen-1.0.1-windows_x86 For Windows 95 OSR 2.5 Or Newer (32-bit Windows)

open95keygen-1.0.1-windows_x86_64 For 64 bit Windows

open95keygen-1.0.1-linux_x86 For modern x86 Linux distros

open95keygen-1.0.1-linux_x86_64 For modern x86_64 Linux distros

Source Code


View all releases.


This is a command line program, so on Windows you first must open the or cmd.exe program. Then just drag o95kg.exe into the or cmd.exe window and press the enter or return key.

On Linux, you may be able to just double click the o95kg file to start Open95Keygen. If this does not work, start your terminal program and execute ./o95kg from inside the release directory.

OEM or Retail?

On Windows 95/NT 4.0, if you see the word OEM in between where you enter the Product Key, use the generated OEM Product Key. If you do not see the word OEM when asked to enter a Product Key, use the generated Retail Product Key:

Retail Windows 95 enter key

OEM Windows 95 enter key

Building From Source

Just download the source, cd into the source directory, and execute make.


Open95Keygen is released under the 3-BSD license, see the file license.txt in each release for full info.