I want to write a vbscript that will wait for windows shutdown and intercept to carry out proper action before shutting down. I want this to be in vbscript since am using it for administration.
Much easier than that, ever since Windows 2000 you can use the Group Policy setting (or Local Policy even if you're not in a domain) to set the Shutdown Script which will be called, as the name implies, when someone is trying to shutdown the computer. For more info, check out MSKB #198642.