Hi James, Alright, I've found the cause and it's entirely reproducible: Code: # Start with an empty WinePrefix... export WINEPREFIX=$HOME/.wine-directx9 wine --version # wine-1.3.13 winetricks --version # Winetricks version 20110123. (C) 2007-2010 Dan Kegel et al. LGPL. # Install .NET Framework 2.0 winetricks -q dotnet20 # Regedit starts normally wine regedit # Install directx9 (quiet mode not implemented?) winetricks -q directx9 # NOTE: Need a delay here so winedevice.exe shuts down. wineboot probably works, too. sleep 10 # Running regedit this time you'll get the error: # The program mscorsvw.exe has encountered a serious problem # and needs to close. We are sorry for the inconvenience. wine regedit It looks as though the directx9 install, or the .reg patch following it, causes a "*mscoree (builtin, native)" entry to appear on wincfg's Libraries tab. If you change the override to "*mscoree (native)" the error message goes away. I think this is a WineTricks problem, would you agree? Where should I log the fault? I know "winetricks d3dx9" is recommended over "winetricks directx9", but that only installs a few select DLLs for DirectX. I specifically need the "DirectX for Managed Components" libraries installed, version 1.0.2902.0 in particular, and the d3dx9 install doesn't do that.