It may not be a question of the software. Let me make an assumption:
First, when you uninstall ADE, you really need to empty the TRASH folder,
because ADE will search for certain files when it installs, and if it sees
those files in the TRASH folder, it will reactivate them.
ADE also checks with its parent site, Adobe.com, to validate your Adobe ID
and password during its install. My guess is that there is a difference
between what it sees in its files and what is on the Adobe website, and the
authorization for your computer. Try logging into Adobe.com and see if you
can do that before you re-install ADE. I won't guarantee that it will work,
but it won't hurt to try.... And if it doesn't work, I'd call Adobe Tech
Support with your error code.