Port 3389 — Remote Desktop (RDP)

RDP (Remote Desktop Protocol) on port 3389 gives you full graphical access to a Windows computer from anywhere. You see the desktop, move the mouse, type on the keyboard — as if you were sitting in front of it. Microsoft built it into Windows, and it's the standard way to manage Windows servers, access work computers from home, and administer remote machines.

RDP is only available on Windows Pro, Enterprise, and Server editions as a host. Windows Home edition can connect to other computers via RDP but can't be connected to.

Enable Remote Desktop on Windows

1. Settings → System → Remote Desktop
2. Toggle Enable Remote Desktop to On
3. Note the PC name shown (you'll need it to connect)
4. Make sure your Windows account has a password set

Connect to a Remote PC

From Windows

# Built-in Remote Desktop Connection
# Press Win+R, type:
mstsc

# Or connect directly from command line:
mstsc /v:computer-name-or-ip

From Mac

Download "Microsoft Remote Desktop" from the Mac App Store (free). Add a new PC connection with the hostname or IP address.

From Linux

# Remmina (usually pre-installed on Ubuntu)
remmina

# Or use xfreerdp from command line
xfreerdp /v:192.168.1.100 /u:username

On the Same Network

Use the PC's local IP address (like 192.168.1.100) or its hostname. Find the target PC's IP with ipconfig on that machine.

Security Warning: Never Expose RDP to the Internet

If you need remote access from outside your network, use one of these secure alternatives:

• VPN — Connect to your home/office VPN first, then use RDP over the VPN tunnel. The RDP port never touches the public internet
• SSH tunnel — Forward port 3389 through an SSH connection: ssh -L 3389:target-pc:3389 your-server
• Remote access tools — Chrome Remote Desktop, AnyDesk, or Tailscale provide encrypted remote access without port forwarding
• Azure/AWS — Cloud-hosted RDP through a bastion host with MFA

Change the RDP Port

Some admins change the default port from 3389 to reduce automated scanning (security through obscurity — not a real defense, but reduces noise). This requires a registry edit:

# Open Registry Editor (regedit)
# Navigate to:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

# Change "PortNumber" from 3389 to your preferred port
# Then restart the Remote Desktop Service
# Don't forget to update your Windows Firewall rule

When connecting to a non-default port, append it with a colon: mstsc /v:192.168.1.100:3390

Troubleshooting RDP