Knowledgebase

Basic Pre-Checks
Use the correct Public IP Address of your VPS.

Confirm the RDP Port (default is 3389)—check if it's custom.

Use valid username/password (e.g., Administrator).

Ensure the VPS is running (try ping or check provider dashboard).

Common RDP Errors & Fixes:

1. Connection Fail Issue
   Common Errors:
   "Remote Desktop can't connect to the remote computer"
   Possible Causes:
   VPS may be offline or RDP service not running.

RDP port might be blocked by a firewall.

Fixes:

Restart VPS via dashboard.

Enable RDP: System Properties > Remote.

Open RDP port in firewall:

netsh advfirewall firewall add rule name="RDP" protocol=TCP dir=in localport=3389 action=allow
2. Multiple Login Attempts Failed / IP Blocked 
 Common Errors:
"Too many failed login attempts"

"Your IP has been blocked"

RDP session closes immediately after connecting

VPS unreachable after brute-force or failed logins

Possible Causes:
VPS firewall or security software (like Windows Defender, Fail2Ban, CSF) blocked your IP

Account lockout due to repeated failed password attempts

RDP brute-force protection tools auto-banned your IP

Fixes:

1. Unblock Your IP
   Log in via VPS web console (from your hosting provider panel)

Use PowerShell or CMD to unblock IP:

powershell:

netsh advfirewall firewall delete rule name="BlockIP" remoteip=<your_ip>
If using 3rd-party tools (e.g., Fail2Ban, CSF), remove your IP from their ban list:

CSF: csf -dr <your_ip> or csf -tr <your_ip>

Fail2Ban: fail2ban-client set unbanip <your_ip>

2. Reset Account Lockout
   Log into the VPS via console

Open lusrmgr.msc (Local Users and Groups)

Check user account status (unlock if locked)

Use PowerShell:

powershell:

Unlock-ADAccount -Identity "Administrator"
3. Review Security Software Logs
Check Windows Event Viewer → Security for failed login audit logs

Look for automated blocks by:

Windows Firewall

Defender ATP

Third-party security tools

Prevent Future Lockouts
Use Strong Passwords and avoid reusing credentials.

Whitelist Trusted IPs in Windows Firewall:

powershell:

New-NetFirewallRule -DisplayName "Allow RDP from Office" -Direction Inbound -Protocol TCP -LocalPort 3389 -RemoteAddress <your_ip> -Action Allow
Change RDP port to reduce brute-force attacks (e.g., 3390, 5500)

Enable Account Lockout Policy with a delay to prevent brute-forcing:

secpol.msc → Account Lockout Policy

Optional: Use RDP Gateway or VPN for secure access

3. Authentication Error or Credentials Issue
   Double-check login credentials (case-sensitive).

Reset the VPS password via your provider.

Ensure user account is not locked or expired.

4. RDP Port not accessible
   Test port with: telnet 3389 or use CanYouSeeMe.org

Open port 3389 in both Windows Firewall and VPS provider’s firewall rules.

5. No Remote Desktop client access licenses available
   Restart "Remote Desktop Licensing" service.

Contact provider to verify CAL (Client Access License) availability.

6. VPS-Side Troubleshooting
   Use Web Console or SSH to access VPS if RDP fails.

Check RDP service via services.msc, restart "Remote Desktop Services".

Enable RDP via PowerShell:

Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Terminal Server" -Name "fDenyTSConnections" -Value 0
Enable-NetFirewallRule -DisplayGroup "Remote Desktop"
Platform-Specific Tips
Windows
Use mstsc.

Save .RDP files for easy access.

Enable clipboard and drive sharing under "Local Resources".

macOS
Use Microsoft Remote Desktop (App Store).

Login format: username@ipaddress.

Android/iOS
Use Microsoft Remote Desktop app.

Ensure mobile network or Wi-Fi allows port 3389.

Advanced Options
Change default RDP port in the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp\PortNumber
Enable Network Level Authentication (NLA) for added security.

Use firewall rules to restrict IP access to RDP.

Disable Windows Defender (Microsoft Defender Antivirus)
Method 1: Using PowerShell (Temporary Disable)
powershell:

Set-MpPreference -DisableRealtimeMonitoring $true
This turns off real-time protection.

Defender will re-enable after a reboot unless permanently disabled.

Method 2: Using Group Policy (Permanent)
Only available on Windows Server or Windows Pro editions
Run gpedit.msc

Navigate to:
Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus

Double-click “Turn off Microsoft Defender Antivirus”

Select Enabled → Click OK

Restart the VPS

Method 3: Registry Editor (Permanent Disable)
Backup the registry before making changes
Run regedit

Navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

Create or modify a DWORD (32-bit) value:

Name: DisableAntiSpyware

Value: 1

Reboot the server

Optional: Disable Defender Services (Advanced)
powershell:

Stop-Service -Name WinDefend -Force
Set-Service -Name WinDefend -StartupType Disabled
This may be restricted unless Defender is already disabled via Group Policy or Registry.
Important Notes
Disabling Defender exposes your VPS to malware/ransomware.

Use only if you have another antivirus or firewall protection in place.

The above points provide a comprehensive guide to troubleshoot common Remote Desktop (RDP) connection issues for Virtual Private Server (VPS) users. Whether you're facing login failures, blocked ports, firewall restrictions, or account lockouts, these steps will help you quickly identify and resolve the problem. Always ensure your VPS is secure, updated, and properly configured to maintain reliable and safe remote access. For persistent issues, don't hesitate to contact your VPS provider's support team with the detailed information you've gathered.