Install TunnelNet OS

This takes a few minutes. Everything on the disk you pick is erased.

Plug the USB stick into the PC and turn it on. Open its start menu to pick the stick: the key is usually F12, F11 or F8, shown on the screen for a moment as the PC starts.
The TunnelNet OS menu appears. Leave it on Install TunnelNet OS: it starts by itself after 10 seconds, or press Enter. If the screen stays black after that, restart and pick Install TunnelNet OS (safe graphics).
The installer lists every disk with its size, its make and what is on it now. Pick the disk by its size and what's on it, not by its short name, because the names can change between starts.
Type the disk's short name (for example sda) and press Enter. A typo just asks again.
It shows what will be erased. Type the same name again to confirm. Nothing is written until you do.
Choose a password for the router, at least 8 characters, and type it twice. Pick a long one and write it down: you need it to sign in at the router's own screen, and from other computers (see Sign in to the router from your computer).
Wait until it says TunnelNet is installed. Remove the USB stick and reboot. In our tests this took about 3 minutes.
Take out the stick and restart the PC (press Ctrl+Alt+Delete, or the power button). It now starts from its own disk.

Want to look around first without changing the PC? Pick Try TunnelNet OS live in the menu instead. Nothing is saved when you turn it off.