This is the preference.txt and the path is
C:\Users\Pamela\AppData\Roaming\Processing
I deleted the whole processing folder from the roaming so I think thats everything I could possibly uninstall along with the actual program which is in
H:\processing-3.5.4-windows64\processing-3.5.4
What do you mean by reinitation? I just deleted both the folders and then unpacked the zip again.