What to run it all on

These are suggestions from our own installations, not requirements. Everything here has alternatives; these are the ones we reach for.

The machine that shows the tablet

It does not need to be a Windows PC. The tablet is an ordinary web page, so the only real requirement is a modern browser you can lock into kiosk mode. In scenario C, that machine does nothing else at all, making it genuinely cheap.

But our own next build will not use a separate box at all. We are using one PC driving two displays — scenario B — because a single machine is easier to install, supervise, update, and visit. A second box duplicates all that work. Start there unless you have a reason not to.

When you do want a separate box, we have used FydeOS and it worked well. We used it on installations built as scenario C, with a mini-PC behind the touchscreen. It is a ChromeOS-style operating system you install on ordinary x86 or ARM hardware, with kiosk mode built in. You point it at a URL, and it boots straight into that page, full screen, with no desktop to escape to. What it buys you:

  • The lockdown is the OS’s job, not yours. No launcher scripts, browser flags, or registry settings — the things the Windows section below spends a page on are simply not your problem.

  • Modest hardware is enough, and there is no Windows licence.

  • It updates and reboots like an appliance, rather than deciding to install something at 3am.

It is not free, though: the edition with kiosk mode carries a small per-device subscription. It is worth the time Windows lockdown takes, but put it in the budget rather than discovering it.

If you use it, ignore the Windows launcher instructions below entirely and configure FydeOS’s own kiosk mode with the tablet’s URL. Everything on the Promethist side is identical — the page does not know or care what is displaying it.

The same reasoning applies to D and E, where the big screen is also just a browser. In E, both on-site boxes can be this cheap.

The machine that runs Unreal

This must be a capable Windows PC with a real GPU. The thing worth adding to it is something that restarts the app if it ever stops, because an unattended kiosk showing a crash dialog is worse than one showing nothing.

  • Promethist WatchDog — ours, free, and what we would reach for now. It supervises the Unreal process and the tablet browser side by side, restarts either on a crash or a frozen window, performs the scheduled nightly restart, and emails you when it acts. Two things a generic supervisor will not do for you:

    It can be told to shut the kiosk down. One command from the building’s management system or from UPS software — when the power fails, for instance — and it closes every app in your configured order and powers the PC off, instead of the battery dying mid-write and taking a database with it.

    It keeps a record of the connection. A slow kiosk gets blamed on the software first. Watchdog measures its own link on a schedule and keeps a dated log, so when the round trip tripled at 09:00 every weekday you can show it, and the problem lands with whoever owns the network.

    The Promethist Watchdog documentation covers both in full, and the source lives at gitlab.com/promethistai/promethist-watchdog. Ask us for PromethistWatchdog-Setup.exe: it is given directly to partners rather than published for download, which is also why Windows will warn you the first time you run it.

    It is years younger than AlwaysUp and has run on our machines rather than thousands of others, so it has met fewer strange situations. It has been solid on every installation we run, and it does more — which is why we would pick it.

  • AlwaysUp — commercial, long-established, and a genuinely safe choice: a decade of other people’s deployments sit behind it. It runs your program, notices when it dies or hangs, and restarts it. It will not do the two things above. Nothing on the Promethist side cares which one you pick.

Whichever you choose, supervise the tablet browser too, not just Unreal. That turns "a visitor somehow closed the window" from an incident into a two-second gap, and is a far simpler guarantee than trying to make a window impossible to close.

If you are streaming (D or E), give the same supervisor a scheduled restart as well as a restart-when-it-dies. See streaming leaks memory, which is also where the flag that stops the leak lives.