Guide: Setting up SSH on Windows and Accessing it from Another Computer

1. Enable the OpenSSH Server on Windows (Server Machine)

Windows 10 (1809+) and Windows 11 come with OpenSSH built-in but not always enabled.

Open Settings
- Press Win + I → Go to Apps → Optional features.
Install OpenSSH Server
- Scroll down and check if OpenSSH Server is installed.
- If not, click Add a feature → Search for OpenSSH Server → Install.
Start and Enable the SSH Service
- Open Services (Win + R, type services.msc).
- Find OpenSSH SSH Server.
- Right-click → Start.
- To make it auto-start on boot: Right-click → Properties → Set Startup type to Automatic.

Check the Firewall

Open PowerShell as Administrator and run:
```
Get-NetFirewallRule -Name *ssh*
```

If needed, allow SSH explicitly:

New-NetFirewallRule -Name sshd -DisplayName 'OpenSSH Server' -Enabled True -Direction Inbound -Protocol TCP -Action Allow -LocalPort 22

2. Find Your Windows Machine's IP Address

On the server machine, open Command Prompt or PowerShell and run:

ipconfig

Look for your IPv4 Address (e.g., 192.168.1.50).

3. Connect from Another Computer (Client Machine)

From Linux / macOS

Open a terminal and run:

ssh username@192.168.1.50

Replace username with your Windows account username.
Replace 192.168.1.50 with the Windows machine's IP.

If prompted with a fingerprint warning → type yes. Enter your Windows password.

From Another Windows Computer

Open PowerShell.
Run:
```
ssh username@192.168.1.50
```

4. (Optional but Recommended) Set Up Key-Based Authentication

This avoids typing a password every time.

On Client Machine generate SSH keys:
```
ssh-keygen
```
- Press Enter to accept defaults → keys saved in ~/.ssh/id_rsa.
Copy the Public Key to Windows
- On the client, run:
```
ssh-copy-id username@192.168.1.50
```
  (If ssh-copy-id isn't available, just copy the contents of ~/.ssh/id_rsa.pub manually).
- On the Windows server:
  - Create directory (if not exists):
```
mkdir C:\Users\username\.ssh
```
  - Paste your public key into a file called authorized_keys:
```
notepad C:\Users\username\.ssh\authorized_keys
```
- Ensure permissions are correct:
```
icacls C:\Users\username\.ssh /inheritance:r
icacls C:\Users\username\.ssh /grant "$($env:USERNAME):(R,W)"
```
Now you can log in without a password:
```
ssh username@192.168.1.50
```

5. (Optional) Access Over the Internet

If you want to connect from outside your local network:

Log in to your router and port-forward TCP port 22 to your Windows machine's IP.
Find your public IP (e.g., visit whatismyip.com).
From the client:
```
ssh username@<your-public-ip>
```

⚠️ Security Warning: Exposing SSH directly to the internet can be risky. Change the port, use key-based authentication, or set up a VPN for safety.