Originally Posted by
Fidodido1966 Please answer only if you know exactly how to resolve this.
Probably why no one has answered.
If you're still having issues, it would be helpful to have additional information to be able to troubleshoot your issue in order to assist properly.
If you have a manufacturer pre-built PC, it would be helpful to know the make and model of that PC. It would also be helpful to know more about the graphics hardware. Is this a PC with graphics embedded on the motherboard? Or do you have a dedicated graphics card? Multiple dedicated graphics cards? What is the make/model of any and all graphics cards that are installed in the PC? What is the manufacturer software and version for the graphics drivers installed? What is the make/model of the working monitor on which the resolution is changing?
Graphics drivers from varying manufacturers are notorious for causing issues just like this. Sometimes the most recent graphics driver is the one that will resolve your issue. Sometimes you have to make sure you have a driver that prior to the most recent, sometimes by one or two releases.
If you still need assistance, provide some additional information and we'll do our best to help.