How can I connect to OS X 10.6 from a Windows server 2008 using VNC over the internet? I have an apple Mac-mini 10.6 and 10.7 with me. when i am trying to connect Mac-mini from Windows server 2008 using vnc server over the internet from my windows machine using http://ipaddress-of Mac:5800/, the connection is not set up. 

Please anyone help on this.
Any help will be highly appreciated.
Have you enabled the option in System Preferences? You set it in Sharing -> Screen Sharing, this enables the VNC server under OS X and opens the port for it.