Bochs is a highly portable open source IA-32 (x86) PC emulator written in C++, that runs on most popular platforms. It includes emulation of the Intel x86 CPU, common I/O devices, and a custom BIOS. Bochs can be compiled to emulate many different x86 CPUs, from early 386 to the most recent x86-64 Intel and AMD processors which may even not reached the market yet. Bochs is capable of running most Operating Systems inside the emulation including Linux, DOS or Microsoft Windows. Bochs was originally written by Kevin Lawton and is currently maintained by this project. Bochs can be compiled and used in a variety of modes, some which are still in development. The 'typical' use of bochs is to provide complete x86 PC emulation, including the x86 processor, hardware devices, and memory. This allows you to run OS's and software within the emulator on your workstation, much like you have a machine inside of a machine. For instance, let's say your workstation is a Unix/X11 workstation, but you want to run Win'95 applications. Bochs will allow you to run Win 95 and associated software on your Unix/X11 workstation, displaying a window on your workstation, simulating a monitor on a PC.
What's new in 3.1
Brief summary of changes: - CPU: Implemented FRED, USER_MSR, MOVRS, AMX-FP8 ISA extensions emulation - CPU: Implemented MS-DOS Compatibility mode for handling x87 FPU exceptions, external logic handles FERR# and IGNNE# pins if enabled The 'extfpuirq' plugin is now always loaded if FPU is present - CPUDB: Added new Wildcat Lake CPU definition featuring FRED, WRMSRNS and MSRLIST - Bugfixes for CPU emulation correctness (critical bugfixes for emulation of XSAVEC/XSAVES, PKeys, AVX BMI1/BMI2, AVX512, AMX, UINTR, CET and SVM) - Increased maximum supported host memory size to 8192 MB (was 2048 MB) - Added UEFI/OVMF firmware support to Bochs through QEMU-compatible fw_cfg device This enables booting UEFI operating systems including Windows Server 2025 and modern Linux distributions with OVMF firmware. - Added basic support for GeForce 3D card emulation (4 AGP models, 2D almost complete, 3D still WIP) - AGP support in i440BX chipset now almost correctly implemented - Many fixes in the devices code (PCI, VGA, Voodoo, hard drive, floppy, USB) - VHDX disk image support added - BIOS fixes for PCI/AGP init and ACPI tables - LGPL'd VGABIOS updated to version 0.9d - Updated SeaBIOS ROM image to current version 1.16.0
Brief summary : - Include Bochs debugger support in all release binaries. Bochs internal debugger and Bochs GUI debugger are compiled in by default and there are no special Bochs binaries with internal debugger support anymore. - Integrated softfloat3e library replacing older softfloat2a fpu-emulation code - Bugfixes for CPU emulation correctness (critical bugfixes for VMX, WAITPKG, LASS, XSAVEC/XSAVES, CPUID and SHA1 ISA implementation) - Added emulation of missing AMD 3DNow! instructions - Implemented AVX512_FP16 Intel instruction set based on softfloat3e library (enabled in Xeon Sapphire Rapids CPU definition) - Implemented MONITORLESS MWAIT instructions support - Implemented initial support for AVX10_1 + AVX10_2 ISA extensions and AVX10 CPUID leaf 0x24 (AVX10_1 first to be enabled in Xeon Granite Rapids) - Implemented AMX-TF32 and AMX-AVX512 ISA extensions - Implemented RAO-INT ISA and MSR_IMM ISA extensions - CPUID: Added new CPU definitions: for i386, i486DX4, AMD Athlon XP and Intel Core i5 Arrow Lake CPUs - CPUID: Support for enabling/disabling of one or more CPU features from CPUID configuration (see "add_features" and "exclude_features" in bochsrc sample and documentation) ! CPUID: Old bx_generic CPUID model is deprecated with all associated .bochsrc CPUID configuration options, use pre-defined CPU models instead - Several fixes and improvements for the Cirrus and Voodoo emulation …
Frequently asked questions
Is Bochs free?
Yes. Bochs is free and open-source software released under the LGPL-2.1 license.
What is the latest version of Bochs?
The latest version is 3.1, released on Aug 23, 2026.
Is it safe to download Bochs?
The download button links to the official installer published on github.com, the same file Windows Package Manager installs. You can verify the downloaded file by comparing its SHA-256 checksum with ccbec06ec5baa81064cfe7c91862d0027b5033dbfa0b773d22e8be92094fdbb5.
Which Windows versions does Bochs support?
Bochs runs on Windows and is available for 64-bit (x64) systems.
How do I install Bochs silently?
Run the offline installer with "Bochs-win64-3.1.exe" /S, or install it with Windows Package Manager: winget install --id=Bochs.Bochs -e --silent.
How do I uninstall Bochs?
Open Settings › Apps › Installed apps, find Bochs and select Uninstall. From the command line, run winget uninstall --id=Bochs.Bochs -e.
Alternatives to Bochs
Other Development kits programs for Windows from different developers.
