Fix Microsoft Train Simulator registry path errors safely with Regedit, including the correct 32-/64-bit key, backup steps and recovery.
Use Regedit to fix Microsoft Train Simulator (MSTS) only when its installation path is missing or wrong—usually after the game was moved or reinstalled. Back up the MSTS registry branch, find its 32-bit installation key, and correct the existing Path value so it points to the folder containing train.exe.
When does a Regedit fix actually help MSTS?
A registry repair helps when Windows, an MSTS update or an add-on installer cannot locate Microsoft Train Simulator. Typical signs include:
- An add-on reports that MSTS is not installed.
- An updater selects an old or nonexistent Train Simulator folder.
- The installation was copied or moved to another drive.
- The registry still points to a previous installation.
Regedit will not repair missing game files, broken routes, faulty consists, graphics-driver problems or incompatible add-ons. If the failure began after installing MSTS on a newer operating system, check our MSTS installation and compatibility guidance for Windows 11 before changing the registry.
How do you repair the MSTS registry path?
Repair the existing Path string so it contains the real MSTS root folder, not the path to the executable itself.
| Windows type | Usual MSTS registry key |
|---|---|
| 64-bit Windows | HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Microsoft Games\Train Simulator\1.0 |
| 32-bit Windows | HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Games\Train Simulator\1.0 |
MSTS is a 32-bit application, which is why its key normally appears beneath WOW6432Node on 64-bit Windows. A mistake we see frequently is editing the similar-looking non-WOW6432Node branch, which the game and its 32-bit installers may never read.
- Find the real MSTS folder. In File Explorer, locate the directory containing
train.exe. A complete installation will normally also contain folders such asGLOBAL,ROUTESandTRAINS. - Close MSTS and its installers. Registry changes should be made while the game, launchers and add-on setup programs are closed.
- Open Registry Editor. Press
Windows+R, enterregeditand approve the administrator prompt. - Open the appropriate key. Use the 64-bit or 32-bit location shown above. Do not create copies in both locations merely to make an installer detect the game.
- Back up the branch. Select the
1.0key, choose File > Export, select the option to export the chosen branch and save the.regfile somewhere safe. - Edit the installation path. In the right pane, double-click the string value named
Path. Replace its data with the full MSTS root folder, such asC:\MSTSif that is wheretrain.exeresides. Do not add quotation marks and do not appendtrain.exe. - Close Regedit and retest. Start the affected updater, add-on installer or MSTS again. A Windows restart is not normally required because a newly launched process reads the updated value.
Changing this value does not move the installation. The files must already exist at the path you enter, and old desktop shortcuts may still need correcting separately.
What should you avoid changing in Regedit?
Change only the MSTS value that is demonstrably wrong, because neighbouring entries can control version, language, installation media or renderer settings.
- Do not change
CDPath, version, product-identification or renderer entries to solve an installation-folder problem. - Do not paste a path copied with surrounding quotation marks.
- Do not point
Pathattrain.exe; it must identify the containing folder. - Do not import an unknown registry file. It may contain another user's drive letters, folders or product data.
- Do not edit every entry containing the old drive letter. Some may belong to unrelated software.
Keep the exported backup private because an installation branch may contain product information. Importing that backup can restore modified values, although a .reg import merges entries rather than providing a complete snapshot rollback.
What if the Train Simulator key or Path value is missing?
Create Path manually only when the 1.0 key already exists and you have confirmed that the installation folder is complete.
Right-click an empty area in the right pane, choose New > String Value, name it Path, then give it the MSTS root directory as its data. If the entire Microsoft Train Simulator registry branch is absent, we recommend repairing or reinstalling MSTS instead of fabricating the whole key tree; the installer may need to register other values as well.
This distinction matters after manually copying MSTS from another computer. Creating Path may satisfy a simple add-on installer, but it does not register every component, install required runtime files or correct permissions.
Why does MSTS still fail after correcting the path?
A correct registry path does not repair an unrelated launch, route or add-on failure. Work through our broader train-simulator failure checks if train.exe still will not start, paying particular attention to damaged settings, permissions and recently installed content.
If the original executable remains troublesome on modern Windows, installing and configuring Open Rails for MSTS content is a practical alternative. Open Rails uses the routes, trains and activities from an existing content folder without relying on the original MSTS executable for normal operation.