This is definitely a “must have” tool for anyone designing websites, or writing client-side scripts, and testing with Internet Explorer.

Download details: Internet Explorer Developer Toolbar Beta

I stumbled across this link some time ago, and have used this quite a bit. Maybe you will find it equally useful.

Basically this is a driver and a config app from Microsoft which allows you to mount cd rom image files as a virtual drive. There’s other tools out there (Nero has an image tool that comes to mind), but this one’s freely available.
Download Here