I am not sure if these .net framework files are part of the automatic updates. I "lost" my tuner after a clean reinstall of XP SP2 and I have a MCE PC. On the microsoft update website there is an option to install .net framework files and I am sure these are needed - certainly for MCE PC's. The update is quite long and I think starts at 1 and goes up to 3.5 versions of the .net framework files. I think it would be worth trying the full update, over the top of what you have. (Maybe create a system restore point first.Not sure why your installation failed.