When I connected my Laptop to a 4k TV with a HDMI cable I tried different resolutions for the TV. Of course I tried the 4k resolution just to see if there is any noticeable difference and thinking that if I don't like the performance I can always change it back to 1080p. Before I applied the 4k resolution I changed the settings to "Second screen only" ( really bad choice) and right after I changed it, my TV screen went white / a light grey. After I disconnect the hdmi cable my laptop monitor stays white for a few seconds than it goes into the lockscreen (fully usable after that).
The problem is that because I changed the settings to second screen only, every time I connect my laptop to the TV it automatically changes the settings to that mode and the TV resolution to 4k, so I can't go in the display settings and change the resolution back.
How can I reset the TV's settings so that windows will think that is the first time I'm connecting to it?