✦ Four steps

1. Unzip somewhere you own. C:\Users\you\Games\haven is ideal. Skip Program Files, where Windows will not let the patcher write to itself, and skip Desktop and Documents, which OneDrive will sync out from under a patch.
2. Make an account. Register here. A name and a password, nothing else.
3. Patch once. Open the patcher, let it settle, then press Start. Only the first run is slow.
4. Use the same details. The login you registered here is the login the game expects.

❖ If it will not start

Black screen or an instant crash: run opensetup.exe from the client folder and switch the renderer to DirectX 9. If a patch keeps vanishing, your antivirus is eating it, so add the folder to its exclusions.