I have Windows 7 Home premium - Following a recent Windows update (I think) when in Windows Explorer, and I double click a FOLDER in the right panel, Paint Shop Pro opens. - When I right click on a folder, the list is now headed with "Browse using Paint Shop Pro". Paint Shop Pro also opens when I click Start > Control Panel and also many other Start options. When I uninstall Paint Shop Pro all seems normal but re-installing PSP, the problem is back again
For some reason, your operating system has linked PSP to some actions, you need to change that: go to the Control Panel, then Programs, then Predetermined Programs (i use a Spanish version of Windows, so the names might be slightly different on your PC), then "Establish predetermined programs". Not exactly sure what option you need to touch in there, but if you select the offending program (PSP) in the list, it should give you the option of un-linking it. Hope it helps!
Control Panel "Programs and Features" doesnt have a Predermined Programs option. I've tried changing default programs etc both in Control Panel sections "Folder Options" and "Default Programs" I also uninstalled PSP, then using regedit, I deleted quite a few PSP keys and values until I couldnt find any more all is fine - then reinstalled psp and the problem back again
Ok, sorry, my Windows is in Spanish, so not sure how the items in the menus are named in English. Anyhow, this is something you want to address from the "Default programs" section of the Control Panel (the classical control panel, not the new Configuration section of windows 10; to open the classical control panel, press WIN and type "control" and hit ENTER). (Control Panel > Programs > Default programs > Set default programs). There you have a list of all installed programs, and you should have PSP too. Once you select a program, you have 2 options, "Set as default" and "Choose default options". I would think here in that second link you should be able to find the solution.