http://www.bleepingcomputer.com/combofix/how-to-use-combofix
Download, follow the directions, good to go.
I’m dubious about the ability of any program to undo all the damage I saw. In a business environment is cheaper just to reinstall Windows. You know its clean when you’re done.
Next time I’ll have recent backups of the system state. Fortunately, mission critical documents are kept on the server and backed up.