Did you delete the FSX directory? If not, back up whatever files you want to keep, uninstall again and delete the directory. Try re installing. If you still get the error, call Microsoft.Sorry you are having so much trouble.God bless,Earl

I found a solution on the Microsoft website, I've re-installed FSX again and it seems 'complete' now. But I am not downloading any non-default aircraft again, I am playing it safe esp after all the tweaks after SP1 and then the subsequent uninstall of SP1 I did a few weeks ago.I think once they have produced a fix for the night lights bug in the default 738 I will then be quite happy with FSX for my needs.