VNCloop.cmd 

The .cmd format is a "Command File" or "Batch File" containing command-line instructions. Some command files could harm your computer. This one won't. Download it to your desktop, scan it for viruses (on principle) and then open it in Notepad - it's just text. You can look up individual commands here:
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/ntcmds.mspx?mfr=true
... but I had to use some quite arcane syntax to get it to do what I wanted!
Phil