cyberpunk 2077 on 8.1 with almost native performance

[Jaguarek62]

# [Windows 8.1 x64] Cyberpunk 2077 2.31 Steam compatibility patch

I am publishing an experimental compatibility package for **Cyberpunk 2077
2.31 on Windows 8.1 x64**, tested against the Steam public build `20383525`.

**Download:** [https://drive.google.com/file/d/1UFNrcPSWhEqu0jUJwUWHz1tm5gOuMK-v/view?usp=sharing]

**ZIP SHA-256:** `5D8543335269D86B7456B60B6E6A3908C6C296B186DB93F8EF25EA38D371745E`

> This release was tested only on **Windows 8.1 x64**, so that is the only
> operating system for which it is currently recommended. The installer rejects
> other Windows versions and unsupported game files.

## What it fixes

The package provides a D3D12On7 raster path for the tested Steam build and fixes the
known presentation problem where Cyberpunk appears frozen and updates only when
another window is dragged over it. The game can be launched normally with
Steam's **Play** button after adding the launch option printed by the installer.

## Performance

On my tested machine, performance is close to running the game on Windows 10.
It is dramatically better than my older Cyberpunk 1.63 compatibility setup,
which delivered roughly half performance on the same machine.

This is an observed real-world comparison, **not a controlled or standardized
benchmark**. Results will vary with GPU, driver, settings and system setup.

## Tested setup

- Windows 8.1 x64
- Cyberpunk 2077 2.31, Steam build `20383525`
- GeForce RTX 2060
- NVIDIA driver `474.11`
- 1920 x 1080
- Raster rendering only

Other GPUs and drivers, GOG/Epic releases, hybrid graphics and other operating
systems have not been tested.

## Required: official D3D12On7 1.1.0 package

Download Microsoft's official
[`Microsoft.Direct3D.D3D12On7` 1.1.0 NuGet package](https://www.nuget.org/packages/Microsoft.Direct3D.D3D12On7/1.1.0)
separately and save the unchanged file next to `Install.cmd` as:

`Microsoft.Direct3D.D3D12On7.1.1.0.nupkg`

Expected package SHA-256:
`C0C4D597537ECC1C777FA3B5523E5CCDE0B9984B88FB9F37B2385E1D687BF536`

The Microsoft package is not bundled with this patch.

## Required: SecondSystem

SecondSystem must already be installed and active. **It is not bundled with the
patch.** Obtain it separately here:

[SecondSystem from win32's Patreon](https://patreon.com/win32?utm_medium=clipboard_copy&utm_source=copyLink&utm_campaign=creatorshare_fan&utm_content=join_link)

Please support its developer and follow the terms provided with it.

## Installation

1. Extract the complete ZIP.
2. Download the official D3D12On7 package above and place it beside
   `Install.cmd`.
3. Install and activate SecondSystem.
4. Exit both Cyberpunk 2077 and Steam completely.
5. Run `Install.cmd`.
6. Copy the exact Steam Launch Options value printed at the end.
7. Paste it into **Steam > Cyberpunk 2077 > Properties > General > Launch
   Options**.
8. Start the game with Steam's **Play** button.

Do not append custom arguments; the included launcher intentionally uses only
the fixed, validated command line.

The installer validates the exact game/runtime hashes and stops before changing
anything if the files are unsupported. It keeps all compatibility files local
to the game directory and creates a verified uninstall record.

## Important limitations

The following features must remain disabled:

- Ray tracing and path tracing
- DLSS
- NVIDIA Reflex
- Frame Generation, including XeSS Frame Generation

This release is for raster rendering. Cyberpunk 2.31's newer Agility SDK path is
not a Windows 8.1 target, so modern features that depend on it are outside this
patch's scope.

## Removal and game updates

Close the game and Steam, run `Uninstall.cmd`, then clear Steam Launch Options.
The uninstaller restores any files it backed up and reverses its SecondSystem
mappings.

The package is locked to Steam build `20383525`. The launcher compares the full
contents of the current executable with its validated local copy and refuses a
mismatch. After a Steam update, uninstall this release and wait for a version
explicitly validated for the new build; do not remove the version/hash safety
checks.

## What is and is not included

The ZIP contains the original open-source proxy, launcher, installer scripts,
source code, documentation and notices. It does **not** include:

- Cyberpunk 2077 files
- Microsoft D3D12On7 or D3D11On12 binaries
- SecondSystem
- Steam files
- any DRM bypass

A legal Steam copy of the game is required. The installer extracts the runtime
inputs from the official NuGet package separately supplied by the user and
creates a local working copy. Microsoft terms still apply and may restrict this
use or modification; this is not legal advice.

Full installation, troubleshooting, technical and checksum information is in
the included `README.md`.