My telefunken model TPM107B is refusing to show PC on the monitor only show the window starup and towards the end of windows were you have to put the password on it shows a NOT SUPPORTED and switches itself off,I have tried to change to Window XP and visa versa Window 7 .when removing the VGA cable from tv monitor and put it back PC monitor it shows it's on,plz help Emmanuel mbodigelo@icloud.com