I have installed Debian 10 (XFCE) on an old computer and now after a year of use although I put right user and password it reappear the window that asks user and password. I entered as root and it goes on with a desktop where I can work. There, on Terminal, I tried to change password of user passwd "user" (my name), but it doesn't accept other passwords. Only the old password! Then I reboot and again it asks user and password without letting me enter in the "user" desktop. Where can I look to solve this problem? Thanks to all
Francesco