Sorry typo! I mean uninstall everything and then restart/reboot the computer, before installing Processing again.
Normally the folder “processing-3.5.4” is placed in the drive that contains Windows (C?) in the folder “Program Files” (On my PC “C:\Program Files\processing-3.5.4”) This folder contains the executable processing.exe com tools etc.
Another folder that contains the Sketchbook you can place where you want, setting it in the IDE menu/preferences dialog.
I saw that yours is saved in “C:\Users\Pamela\Documents\Processing”, meaning that your main Windows drive is ‘C’, so that’s where the executable should be installed. Not in drive ‘H’)