Installing Fusion
What you need¶
- Windows 10 or 11, 64-bit.
- A graphics card with DirectX 12 (most from 2016 on). Fusion and your games share it.
- Enough memory for two games at once. 16 GB of RAM works for most pairs; Fusion tells you how much each scenario uses, and puts games to sleep when memory runs low.
- The games you want to fuse, installed. Steam games are found by themselves; others are found by their router.
You don't need Steam for Fusion itself, and you don't need administrator rights.
Download and install¶
- Go to steonmod.com/download and click Download for Windows. You get
Fusion-Setup-<version>.exe. - Run it. Windows may say "Windows protected your PC": the installer isn't code-signed yet. Click More info, then Run anyway.
- Answer Yes when it asks to install. It takes a few seconds and opens Fusion.
Where things go¶
| What | Where |
|---|---|
| Fusion itself | %LOCALAPPDATA%\Programs\Fusion (the current version and the one before) |
| Your settings, keys, installed content, crash reports | %LOCALAPPDATA%\Fusion |
| Shortcuts | Start menu and desktop: Fusion |
Double-clicking a .fusion file opens it in Fusion's Content screen.
Updates¶
Each time it starts, Fusion asks steonmod.com whether there's a newer version. If there is, it shows what's new and asks first. While it downloads you see a progress bar, and Cancel keeps the version you have. Every update is signed by SteonMod; Fusion refuses one that isn't, and keeps the version before so it can go back if the new one crashes.
You can change or empty the update address in Settings → Updates (empty: Fusion never looks).
Uninstalling¶
Open Windows' Settings → Apps → Installed apps, find Fusion, and choose Uninstall. It removes Fusion, its shortcuts and its file type. It asks before removing your own data (%LOCALAPPDATA%\Fusion) and keeps it unless you say so.
Games that Fusion set up keep their setup until you undo it: in My Games, press Undo setup on each one before uninstalling, and they're back as they were. See My Games.
If Fusion crashes¶
Fusion's launcher notices, saves a report in %LOCALAPPDATA%\Fusion\crashes\, and tells you. If the crash came right after an update, it offers to go back to the version before. Please send the report along when you tell us what happened (Fixing problems).