Robert Bell
I reason that I asked you to test again 9 now that you have 12 installed relates to some who have found that in some cases such an arrangement gets the original program to run again.
With 12 closed (but installed on the same computer as 9.0/9.0.1), follow this path to the Adobe Premiere Elements 9.0.exe and Adobe Premiere Elements.exe file and double click each separately to see if the program can be opened successfully with either.
Local Disk C
Program Files (x86)
Adobe
Premiere Elements 9
and in the Premiere Elements 9 Folder are these two files. The Adobe Premiere Elements 9.exe opens 9 to the Welcome Screen. And the Adobe Premiere Elements.exe bypasses the Welcome Screen.
Please let us know if either of those work for you.
More in the light of day.
ATR