I’d like to add how I resolved this issue because for me none of the above actions worked.
My older netbook is '''Asus X201E''' (with Windows 10) - HDMI connected to '''Samsung 27 Inch monitor'''.
Surprisingly, this finally worked (should have tried first): Desktop right click - Graphics Options - Output to - Digital Television (select)
(After that, many more resolutions became available in the Graphics gui, and even bloody Win10 warned that my resolution was not optimal at this point …)