The new update created a new user on my Winows 10 PC

After this update a new, and totally unknown user emerged on my PC. The information from this user folder says it has been created before I bought my PC. It is named by a person's name unknown to me and contains folders with photos, excel-files, music, pdf-files, videos etc. (I bought this new PC this fall.) I tried to delete the new user, but was not allowed to do it. I tried to prevent the user with my F-secure, but the user-folders are protected, and again, I'm not allowed to delete this new, unwanted user on my PC.