Here's a weird problem: At one point I switched Control Panel from the Category view to the Classic view (i.e., icons). After that, Control Panel wouldn't load any more -- it would crash Explorer instantly.
Turned out the problem was a corrupt folder-view entry in the Registry. I went to HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell and deleted Bags and BagsMRU. All was well again.
