Everything MergenHub owns lives under one folder, which makes backup, migration and upgrades simple.

What to back up

Item	Location	Notes
Whole data folder	`C:\ProgramData\MergenHub\`	Project, SCADA, users, settings, license, certificates, logs, historian
Project only	Connectivity › Export → JSON	Channels, devices, tags, alarms, log groups, virtual tags, aliases
SCADA only	SCADA › Export project	Screens, zones, symbol library, bindings
Historian in an external DB	your ODBC database	Back up with the database's own tools

Tip A nightly copy of C:\ProgramData\MergenHub (with the services running is fine; SQLite files are consistent) is enough to rebuild a server from scratch.

Example scheduled task (robocopy, keeps 14 daily copies):

robocopy "C:\ProgramData\MergenHub" "D:\Backups\MergenHub\%date:~-4%%date:~3,2%%date:~0,2%" /MIR /R:1 /W:1 /XD logs
forfiles /P "D:\Backups\MergenHub" /D -14 /C "cmd /c rmdir /s /q @path"

Restore

Install the same or a newer MergenHub version on the target machine.
Stop the three services (sc stop MergenHub).
Replace C:\ProgramData\MergenHub with the backup (keep the new webpki\ if the host name changed).
Start the services. Users, project, screens and history are back.
Re-activate the license on the new hardware (release it on the old machine first, or use Force release in the portal).

Migrating to another server

Same as restore. Points to remember:

OPC UA clients trust the server certificate; a new machine has a new certificate unless you copy pki\own. Clients may need to trust it again.
The web HTTPS certificate is bound to the host name; regenerate with MergenHub.exe gencert "<name>" if the name changed.
Firewall rules are per machine — the installer creates them; see Firewall.

Upgrading

Run the new installer. It:

stops services and the tray app,
replaces program files completely (no stale DLLs),
keeps C:\ProgramData\MergenHub untouched,
migrates old service names if needed,
starts everything again.

Downtime is typically under a minute. Release notes are on the releases page; licensed installations are notified inside the application. Upgrades are free for the life of the license.

Note Downgrading is not supported. Keep the previous installer and a backup if you want a way back.

Project export / import

Connectivity › Export writes the project as JSON; Import reads MergenHub or Kepware JSON exports. Import can replace the project or merge into it (same-named channels are replaced). Passwords inside device settings are exported encrypted with a project key; importing on another server asks for the key.

Uninstalling

Settings › Apps or the uninstaller in the program folder. It stops and removes the three services, removes the firewall rules and the tray autostart, and deletes program files. The data folder is kept so a later reinstall finds everything again. Delete C:\ProgramData\MergenHub by hand if you want a completely clean machine.