"Windows Internals and Advanced Troubleshooting" training
Later this year, SysInternals/WinInternals founder Mark Russinovich and David Solomon are offering a top-notch class on troubleshooting that covers current OS versions as well as upcoming changes to the OS in Vista (next Windows version)
This class appears to be similar to the PDC05 precon session some of us went to last fall, except it is 5-days instead of a 5-hours! If you want to understand Windows to the Nth degree, this is definitely the class.