I advise against using Winbox, there are issues with it, and that’s not just my personal theory.

On the MikroTik download page, a Netinstall tool is available in CLI form.

You can use it to install a new RouterOS image, apply a configuration script, and enable SSH immediately.

Preparation

  1. From MikroTik Download, download Netinstall (CLI Linux) and the Main package (note: the RB750Gr3 uses MMIPS).
  2. Set a static IP on your computer (e.g., 192.168.88.x, where x is not 1) and set the default gateway to 192.168.88.1.

Running Netinstall

In the directory containing your downloaded files, run:

sudo ./netinstall-cli -o -r -a 192.168.88.1 ./routeros-*.npk```

- `-o` – One-time installation (optional)
- `-r` – Use default configuration
- `-a` – IP address assigned to the router
- `./routeros-*.npk` – The downloaded system image file

Next steps:

0. Power off the router.
1. Connect your computer to the `ether1` port on the router.
2. Press and hold the RESET button.
3. Turn on the power while holding RESET until you see the LED:  
    - Flashing
    - Steady
    - Turn off
4. Wait until the terminal displays a message confirming a successful installation.

### Adding a Custom Configuration

Instead of using the `-r` flag (which applies the factory default configuration), use `-s` and provide a file with the .rsc extension.

### Example

Save your desired configuration to a file named `config.rsc`. This is simply a script containing RouterOS commands.
```rsc
/user
set admin password=your_password_here

In my opinion, the best approach is to configure the IP, DHCP server, and enable SSH. I highly recommend using SSH key-based authentication for logging in. You can find useful documentation here.

Alternative - Mac-Telnet

MikroTik devices support a proprietary Mac-Telnet protocol that operates at L2 (meaning it works without an assigned IP address).

There are open-source Mac-Telnet implementations available, though they did not work in my specific case.