A few days ago, I was looking for an imaging software besides commercial solutions like Arconis. And of course it should be open source one, too. David pointed me to http://clonezilla.org/ which was a great hint. After setting up my master machine I was able to clone it to any other machine using two usb keys running the Clonezilla live version.
To flash the live version it onto the usb sticks I used the good tutorial at the clonezilla page. After you start the machine from the usb-key you have the options to either store the hard disk contents of the master machine to an image and restore it on the target machine. Or you can use the ‘disk-to-disk’ functionality and clone the hard disk directly (works over the network). Of course I had the benefit of having only one type of machines in the computer lab. For my purposes I used the ‘disk-to-disk’ method. But I successfully stored an image of the original windows machine and restored it to another machine as well.
All in all, I was more then happy with the outcome and the handling of the software. Of course, when you do this more often you would like to have a broadcast command to do the flashing in one go. But that exercise is left to the reader.