What exactly are you trying to accomplish?
If you just want to view/control the Mac desktop from a Windows machine on the same local network, just turn on Desktop Sharing in the System Preferences, and enable VNC in the advanced box - it's built into OS X; then download one of a number of free/open-source VNC clients for Windows.
If you want remote-over-the-internet access, you can either do some advanced VNC setup on routers, or use something like TeamViewer, Go2MyPC, WebEx, or the like.