RealVNC has RealVNC Personal Edition and RealVNC Enterprise Edition that support Windows Vista, but unfortunately the software programs are not free and require a license and serial key. RealVNC Free Edition does not support Windows Vista, and users have to depends on various workaround to run VNC on Windows Vista. Luckily there is free alternative for users who need to run VNC server on Windows Vista system.
The alternative is UltraVNC (UVNC) version 1.0.4. UltraVNC is similar to RealVNC, both is free download and uses VNC (Virtual Network Computing) protocol to remote control screen of another computer via network or Internet. UltraVNC features more functionalities in addition to remote control, such as an encryption plugin to secure connection between client and server, file transfer support, chat functionality, and various authentication methods. Best of all, UltraVNC is cross-compatible and cross-working with any other client and server implementations of VNC, including RealVNC and TightVNC.
VNC, client or server when installed and ran on Windows Vista, faces various problems and issues such as WinVNC.exe cannot send the Ctrl-Alt-Del sequence, unable to capture logon screen to sign in on boot up due to session isolation security feature in Vista, and due to User Account Control (UAC) privileges elevation feature, VNC executable cannot respond interactively with application and desktop running in higher level of elevation.
UltraVNC has released UltraVNC v1.0.4 release candidates which has added support and compatibility with Windows Vista. The latest RC6 beta build release is pretty stable and fully Windows Vista compatible. If you’ve no confident in test build, the final release of UVNC 1.0.4 is scheduled to go live for free download on January 1, 2008 for 32-bit (x86) edition of Windows Vista, and January 2, 2008 for 64-bit (x64) edition of Windows Vista.
Download Vista-compliant UltraVNC from UVNC.com.
Update: UltraVNC has been updated to support most new operating system.