FileMon saved my career!
Okay, maybe I should be more careful with titles, but it is a catchy one! ;-)
On my fresh pc I had to install the Guidance Automation Extensions (GAX) and during install, my laptop crashed. I know, please don't start about XP vs. Vista anymore. But anyway, after rebooting I tried to install GAX again but got a configuration error. After traveling over a lot of websites that Google suggested, I ended up executing FileMon to see what config file it actually tried to reach. Funny enough the installer accesses about a million files which after searching for .xml and .config files I ended up with a few dozen files spread out over my system in many different folders.
So I scrolled down to the last items that the FileMon reported the installer to have accessed. To my surprise it tried to access machine.config a few lines before the end. The result was that I found that file heavily corrupted. After getting a new one from a colleague, everything was fine again.
Thank you SysInternals and FileMon! And thank you Windows for eating away another hour of production time. And Windows Live Writer for another 5 minutes! o:-)