Thank you for this very detailed and funktional appearing answer within a narrow time frame! Yet another process-related problem ocurred in workin through your problem solution list:
I uninstalled Firefox. Then after a library lookup for *mozilla* I noticed that Thunderbird files are included as well, so I also unistalled Thunderbird preventively. - So far, so good ...
But when I tried to delete the *mozilla*-files, some remained undeleted because of a lack of access privileges. A dialog box entitled »Dateizugriff wurde verweigert« (approx. in english: »file access denied«) appeared.
(this should be a screenshot of the box ... if the image upload via URL was successful ...)
Again I tried to solve that problem via online search but unsuccessfully - a boring topic that occurres frequently and remaines unsolved because I know far too little about that part of the system and it's significance. The main problem in following the statements of the tutorials: There ist no »Besitzer« (engl. »Owner«) tab in the dialog box »Erweiterte Sicherheitseinstellungen« (engl. »extended security settings«) where I should make the modifications (?)!
(another screenshot ...)
There are two undeleted files called »mozilla browser« (each 2 KB) in the directories
both withe the Windows Explorer note »(C:\Windows\WinSxS)«.
I think, if I could sucessfully get the user permission for deleting these files I would be able to manage the rest likewise and continue cleaning the computer. The dialog box says: »Sie muessen die erforderlichen Berechtigungen von "SYSTEM" erhalten um Aenderungen an dieser Datei durchfuehren zu koennen.« (approx. in english: »You have to receive the required privileges from "SYSTEM" to be able to alternate this file.«)
Can you please give me a hint how I could get the necessary access privileges from »SYSTEM« to proceed? - Thanks in advance!