I think virtualization takes you a long way towards the solution to this issue. With Win7 I've gotten into the habit of routinely working on virtual instances u

I think virtualization takes you a long way towards the solution to this issue. With Win7 I've gotten into the habit of routinely working on virtual instances using the boot from .vhd feature. This means that if something goes wrong my host is not impacted and I can revert to an earlier version of my .vhd to solve problems like this one. The standard IT "wait and see" policy makes this something that will take awhile to become common but I think it is the way to go for pretty much any critical path task you do on a Windows PC (other OSes such as OS X have similar features as well but I only use OS X for "media" stuff).