Download UltraVNC Free – Complete Installation and Usage Guide

What is UltraVNC?

UltraVNC is a free, open-source remote desktop software built on the VNC (Virtual Network Computing) protocol. It is one of the most popular remote desktop tools for Windows, allowing you to control a remote computer over LAN or the Internet with just a few clicks.

Unlike Windows Remote Desktop (RDP), which only works on Windows Pro editions and above, UltraVNC runs on every version of Windows — including Home editions. With real-time screen sharing, two-way file transfer, built-in chat, and integrated VPN support, UltraVNC is a comprehensive solution for everything from remote IT support to enterprise system administration.

Core strength: UltraVNC combines the power of VNC with advanced features like AES-encrypted file transfer, Video Hook Driver for blazing-fast screen updates, and built-in VPN for end-to-end encrypted connections — all in a completely free package.

History of UltraVNC

UltraVNC was first developed by Rudi De Vos and Martin Scharpf in 2002, based on the original VNC source code from AT&T Cambridge Research Lab. The goal was to create an enhanced VNC with superior security and performance features compared to other VNC variants like RealVNC and TightVNC.

Key milestones:

• 2002: UltraVNC 1.0.0 released — basic VNC connection, file transfer
• 2004: UltraVNC 1.0.1 added connection encryption via DSM plugin
• 2006: UltraVNC 1.0.2 introduced Video Hook Driver — faster screen refresh
• 2008: UltraVNC 1.0.4 added Repeater — easy NAT/firewall traversal
• 2011: UltraVNC 1.0.9 added Windows 7 support, improved Single Click
• 2015: UltraVNC 1.2.0 complete redesign, modern UI
• 2018: UltraVNC 1.2.2 added AES encryption, improved security
• 2020: UltraVNC 1.3.0 added Windows 10 support, multi-threaded optimization
• 2022: UltraVNC 1.4.0 added Gamma Correction, high-DPI support
• 2024-2026: UltraVNC 1.4.3+ with security updates, Windows 11 support, IPv6 optimization

How it differs from Windows Remote Desktop: UltraVNC does not require Windows Pro, supports multiple concurrent viewers, offers two-way file transfer, and makes Internet connectivity easy with Repeater — whereas RDP limits to one active session, requires complex NAT configuration, and locks out the local user when a remote session is active.

---

Key Features of UltraVNC

Remote Desktop Control

UltraVNC delivers a smooth and responsive remote desktop experience:

Feature	Description
Remote Control	Full mouse and keyboard control of the remote computer in real time
View Only Mode	Watch the remote screen without interaction — ideal for training and monitoring
Full Screen Mode	Display the remote desktop full-screen — work as if you were sitting at the remote PC
Scale Mode	Automatically scale the remote desktop to fit the viewer window
Auto Scaling	Auto-adjust resolution — perfect when local and remote PCs have different resolutions
Multi-Viewer	Multiple users can view/control the same computer simultaneously
Single Click	Generate a small EXE for end users — no installation required, connects instantly
Video Hook Driver	Screen capture driver for faster refresh rates — reduces lag, increases FPS

Two-Way File Transfer

UltraVNC includes built-in secure file transfer between local and remote machines:

Feature	Description
File Transfer	Two-way file transfer between local and remote machines via graphical interface
Drag & Drop	Drag files from your local machine into the viewer window to send them
Queue Management	Manage file transfer queue — pause, cancel, view progress
Auto-Compression	Automatically compresses files before transfer — saves bandwidth
Encrypted Transfer	File transfer over AES-encrypted connection — safe over the Internet

Security

UltraVNC provides multiple layers of security for remote connections:

• AES Encryption: Encrypts the entire VNC connection with AES 256-bit via DSM (Delphi Security Module) plugin
• Dual Passwords: Separate passwords for full control and view-only access
• MS Logon Authentication: Integrates with Windows accounts — authenticate using Windows username/password
• IP Blacklist: Automatically blocks IPs after failed login attempts
• Allow/Deny List: Restrict connections to specific IP addresses only
• Idle Timeout: Automatically disconnect after a period of inactivity
• Blank Screen on Disconnect: Automatically turns off the remote monitor when connected — protects privacy

Advanced Features

UltraVNC Repeater: A relay server that enables VNC connections through NAT and firewalls without port forwarding. Ideal for IT support when the client machine is behind a corporate firewall without a public IP.

UltraVNC VPN: Built-in VPN feature (based on OpenVPN) — creates an encrypted tunnel between two machines before establishing the VNC connection. Provides absolute security when connecting over the Internet.

MS Logon II: Enhanced authentication system using Windows credentials — supports Active Directory and Group Policy. Perfect for enterprises that need centralized access management.

Auto Reconnect: Automatically reconnects when the connection drops — no need to manually set up the connection again.

---

UltraVNC vs Other Remote Desktop Tools

Criteria	UltraVNC	Windows RDP	TeamViewer
Price	Free (GPLv2)	Free (Pro+ edition)	Free (personal) / from $50.88/month (business)
Platform	Windows (Server, Repeater on Linux)	Windows	Windows, macOS, Linux, Mobile
Windows Requirement	All editions (including Home)	Pro/Enterprise/Education	All editions
Multi-Viewer	Yes — unlimited	No — 1 session	Yes — paid
File Transfer	Yes — two-way, encrypted	Yes — via RDP drive mapping	Yes — two-way (limited on free)
Built-in Chat	Yes	No	Yes
Encryption	AES 256-bit (DSM plugin)	RDP encryption (TLS)	RSA 2048 + AES 256-bit
Single Click	Yes — customizable EXE	No	Yes — QuickSupport
Repeater/Proxy	Yes — self-hostable	RD Gateway	No (uses TeamViewer servers)
Built-in VPN	Yes	No	No
Open Source	Yes (GPLv2)	No	No

---

How to Download and Install UltraVNC

How to Download UltraVNC Free

You can download UltraVNC from the official website using the Download button at the top of this article. Additional download options:

• Official site: uvnc.com
• Portable: Portable version available on the official site — runs without installation
• SourceForge: sourceforge.net/projects/ultravnc

Warning: Only download UltraVNC from uvnc.com or SourceForge. Fake download sites often bundle malware or adware. UltraVNC is completely free under the GPLv2 license.

System Requirements

Operating System	Minimum Requirements	Recommended
Windows (Server)	Windows 7, 512MB RAM, 50MB storage	Windows 10/11, 2GB RAM, SSD
Windows (Viewer)	Windows 7, 256MB RAM, 20MB storage	Windows 10/11, 1GB RAM
Windows Server	Windows Server 2008+, 512MB RAM	Windows Server 2016+, 2GB RAM

Installing UltraVNC

Step 1 — Download the installer: Download UltraVNC_1_4_36_X64_Setup.exe (~10MB) from uvnc.com.

Step 2 — Run the installer: Double-click the downloaded file. The installer displays the following options:

• UltraVNC Server: Install the serving component — the computer that will be controlled remotely
• UltraVNC Viewer: Install the client component — the computer used to control others
• UltraVNC Repeater: Install the relay server — for connections through NAT/firewall
• UltraVNC VPN: Install the built-in VPN feature

Choose Full Installation for all components, or select only Server or Viewer based on your needs.

Step 3 — Configure the Server (computer to be controlled): After installation, UltraVNC Server runs automatically. Right-click the UltraVNC icon in the system tray and select Admin Properties:

1. Security tab:
   • Set Password (control password)
   • Set View-Only Password (optional)
2. Screen Capture tab:
   • Select Video Hook Driver for optimal performance
3. Input/File Transfer tab:
   • Enable File Transfer if needed

Step 4 — Connect from Viewer (controlling computer): Open UltraVNC Viewer from the Start Menu:

1. Enter the IP Address or hostname of the Server machine
2. Select Encryption if needed (DSM plugin)
3. Click Connect
4. Enter the password set on the Server
5. The remote screen appears — you can control it immediately

---

How to Use UltraVNC

Basic Connection

Connecting over LAN:

1. Find the Server's IP: Open cmd > ipconfig — note the IPv4 address
2. On the Viewer machine: Open UltraVNC Viewer, enter the IP, click Connect
3. Enter the password — connection established

Connecting over the Internet:

1. Method 1 — Port Forwarding:
   • On your router, forward port 5900 (or a custom port) to the Server's IP
   • Connect from Viewer using the public IP: 123.45.67.89::5900
2. Method 2 — UltraVNC Repeater:
   • Install Repeater on a VPS/server with a public IP
   • The Server connects to the Repeater
   • The Viewer connects through the Repeater
   • No port forwarding needed — easily bypass NAT

Security tip: Always enable encryption (DSM plugin) and use strong passwords when connecting over the Internet. Never use unencrypted VNC over the Internet — your data can be intercepted.

File Transfer

1. In the connected UltraVNC Viewer window, click the File Transfer button on the toolbar
2. The UltraVNC File Transfer window opens:
   • Left side: local machine directories
   • Right side: remote machine directories
3. Select files/folders and click the arrows to transfer:
   • → Send: Send files from local to remote
   • ← Receive: Receive files from remote to local
4. Monitor progress in the queue at the bottom

Single Click (IT Support)

Single Click lets you generate a small EXE file to send to end users — they just run the file and you can control their machine instantly:

1. Open UltraVNC Server > Create SingleClick Executable
2. Configure:
   • Repeater Address: Repeater server address (if used)
   • Port: Connection port
   • Encryption: Select encryption plugin
3. Click Generate — the EXE file is created
4. Send the file to the end user via email/support
5. The user runs the file — the connection is established automatically

Single Click is invaluable for IT support staff — end users don't need any technical knowledge, they just run the file and you can remote in immediately.

Built-in Chat

1. In the connected Viewer window, click the Chat button on the toolbar
2. The chat window opens — both sides can type and send messages
3. Chat supports Unicode — type in any language normally

This feature is extremely useful when guiding a user through a task during a remote session — no need to make a phone call or message through another app.

Advanced Configuration

UltraVNC Admin Properties (right-click system tray icon):

Tab	Key Options
Security	Control password, view-only password, MS Logon, DSM plugin
Screen Capture	Video Hook Driver, polling mode, CPU usage control
Screen	Disable blank screen on viewer connect, keep aspect ratio
Input/File Transfer	Enable/disable File Transfer, keyboard/mouse pass-through
Connection	Port (default 5900), Auto Reconnect, Idle Timeout
Users & Groups	Access control by Windows account (MS Logon II)
Misc	Logging level, remove wallpaper, remove Aero effects

---

Real-World Applications of UltraVNC

Remote IT Support

UltraVNC is an essential tool for IT support teams. With Single Click, you can remote into a user's machine without requiring them to install complex software. Pair with Everything to quickly find configuration files on the remote machine.

System Administration

System administrators use UltraVNC to manage headless Windows servers. Running as a Windows Service, the UltraVNC Server works even when no user is logged in. For SSH access to Linux servers, check out PuTTY — the powerful SSH client for Windows.

Customer Support

Businesses providing remote technical support use UltraVNC Repeater to manage hundreds of concurrent connections at zero cost — compared to TeamViewer which can cost thousands of dollars per year for commercial licenses.

Remote Work

Employees can remote into their office PCs from home using UltraVNC. The built-in VPN ensures a secure connection. If you use VirtualBox to run virtual machines, UltraVNC can also connect to VMs over the internal network.

Teaching and Training

View Only mode lets instructors share their screen with students without fear of interference. Multi-viewer support allows multiple students to watch simultaneously.

---

Common Issues and Troubleshooting

UltraVNC Server Not Running

• Check if the UltraVNC icon appears in the system tray
• Go to Services.msc — verify the uvnc_service is running
• Re-run the installer and select Repair
• Check Windows Defender Firewall — it may be blocking UltraVNC; add a rule to allow port 5900

Cannot Connect to Server

• Verify the IP address: ipconfig on the Server machine
• Test the port: telnet <IP> 5900 — if it fails, a firewall is blocking the connection
• On Windows: Settings > Privacy & Security > Windows Security > Firewall & network protection > Allow an app through firewall — add UltraVNC Server
• For Internet connections: verify port forwarding on the router, or use Repeater

Slow or Laggy Remote Display

• Enable Video Hook Driver in Admin Properties > Screen Capture
• Reduce color quality: On Viewer, select Options > Colors > 256 Colors (8-bit)
• Enable Auto Scaling if the two machines have different resolutions
• Disable wallpaper and Aero effects on the Server: Admin Properties > Misc > Remove wallpaper/Aero
• Connect over LAN instead of the Internet if possible

File Transfer Not Working

• Verify File Transfer is enabled in Admin Properties > Input/File Transfer
• Try transferring a small file first — if successful, the issue is file size or connection speed
• For large files (>1GB), compress them first with 7-Zip to speed up transfer

DSM Encryption Plugin Errors

• Ensure both Server and Viewer use the same DSM plugin and version
• Default plugin: SecureVNC.dsm — if missing, download from uvnc.com
• Go to Admin Properties > Security > DSM Plugin > select the appropriate plugin
• If encryption is not needed (trusted LAN only), you can disable the DSM plugin

Frequent Disconnections

• Check your network connection — ping the Server to test stability
• Enable Auto Reconnect in Viewer Options
• Increase Idle Timeout if it's set too low
• Use Repeater if the Internet connection is unstable

---

Frequently Asked Questions (FAQ)

Is UltraVNC really free?

Yes. UltraVNC is completely free for all purposes, including commercial use. It is licensed under the GNU General Public License v2 (GPLv2) — you may use, modify, and distribute it freely.

Is UltraVNC safe to use over the Internet?

Yes, if you enable the DSM Encryption plugin (AES 256-bit) and use strong passwords. UltraVNC also includes a built-in VPN for an encrypted tunnel. Never use unencrypted VNC over the Internet.

Does UltraVNC support Vietnamese?

UltraVNC supports full Unicode — you can type Vietnamese in applications on the remote machine normally. However, the software interface itself is currently English only.

What's the difference between UltraVNC Server and Viewer?

UltraVNC Server is installed on the computer that will be controlled remotely. UltraVNC Viewer is installed on the computer used to control other machines. A single machine can have both installed.

Does UltraVNC run on macOS or Linux?

UltraVNC Server runs on Windows. However, UltraVNC Viewer can connect to any VNC Server (including macOS Screen Sharing and Linux VNC Server). Conversely, any VNC Viewer on macOS or Linux can connect to an UltraVNC Server on Windows.

How do I make UltraVNC start automatically with Windows?

UltraVNC Server is installed as a Windows Service (uvnc_service) and starts automatically on boot. No additional configuration is needed. Check Services.msc to verify the service is set to Automatic.

Does UltraVNC limit the number of connections?

UltraVNC Server does not limit the number of concurrent viewer connections. Multiple users can view and control the remote computer simultaneously.

Can I change the default UltraVNC port?

Yes. Go to Admin Properties > Connection > Port Number. The default is 5900. If you change the port, remember to update your firewall rules and port forwarding settings accordingly.

How do I completely uninstall UltraVNC?

Go to Windows Settings > Apps > Installed Apps > UltraVNC > Uninstall. Then delete C:\Program Files\uvnc bvba\UltraVNC if any remnants remain. To remove the service: open cmd as Administrator > sc delete uvnc_service.

How is UltraVNC different from TightVNC or RealVNC?

UltraVNC offers significantly more features: Video Hook Driver for better performance, two-way file transfer, built-in chat, Single Click, Repeater, integrated VPN, and MS Logon II — whereas TightVNC is more basic and RealVNC locks many features behind a paywall.

---

Conclusion

UltraVNC is one of the best free remote desktop software solutions for Windows. With over 20 years of development, UltraVNC has proven its stability, security, and performance superiority over many commercial competitors. Combining open-source freedom with a rich feature set (Video Hook Driver, Single Click, Repeater, integrated VPN, AES encryption) and a completely free price tag, UltraVNC is the number one choice for remote desktop needs.

Whether you are an IT support technician helping customers remotely, a system administrator managing servers, a business looking to save on TeamViewer licensing costs, or an individual needing to remote into their home PC, UltraVNC delivers exceptional performance. Download UltraVNC for free using the Download button at the top of this article.

Combine UltraVNC with other free tools to build a complete remote work toolkit: PuTTY (SSH client), FileZilla (FTP/SFTP), Wireshark (network analysis), Everything (file search), 7-Zip (file archiver), and browse more in our Free Software Downloads category.

Official download link: Download UltraVNC Free