I clicked on "Upgrades"....wanting to see if there were any.
For the 'Windows version'?
The only 'upgrade' available.....is for a MAC (Leopard version).
"Painter Essentials 4" (for Windows).........is very temperamental, to say the least!
It (the software) is very particular!..........................in about how it is being used!
Get it wrong, and 'Error windows'.....pop up.
I am sorry to here you are having problems using PE4. Can you be any more specific as to what you are doing when the error dialogs are popping up?