OpenNT 4.5

OpenNT 4.5 is a compiled build of a modified variant of Windows NT Workstation 4.0, which was created by stephanos. It released on July 28, 2015, and was added to the archive in December 2021.

OpenNT 4.5
Crusty Windows bootleg
The desktop of OpenNT 4.5
The desktop of OpenNT 4.5
Original OSWindows NT Workstation
Release dateJuly 28, 2015
Architecture(s)x86 (32-bit)
File size55 MB
Download linkNT45Wks.iso
Date addedDecember 2021


The OS is a build of OpenNT, an open source variant created from the leaked Windows NT 4.0 source code. Though it is not a true bootleg, it is kept in the archive for its historic value.

Other than the kernel version being changed from 4.00 to 4.50, no modifications have been made to the OS.



  • On some versions of VirtualBox, explorer may stop responding for a long time, but then return to normal.