It seems to be a problem with the Solver Add In.
This is odd, but as I could access the keyboard commands (though still not
see my spreadsheets) I went into Excel options and tried turning off the
addins. Wioth the Solver Add in disabled, Files open normally and excel
opens normally . Once it is reactivated, I'm back to the blue screen. As I
need the solver for my work, can I uninstall it from the system and
re-install it?