One of our executives has a T420s 41717FU running Windows XP SP3 and the discrete graphics card (no Optimus capability since it's XP). He has an external screen connected via a Series 3 Mini Dock. He wants the video configuration to use each screen independently when he is docked. However, when he undocks the laptop to take it with him, and redocks later, it mirrors the video on both screens at the laptop's resolution. I've made sure the drivers are totally up to date as well as the BIOS. I cannot figure out how to make the settings stick. Can anyone please advise?
Welcome to the community and thank you for posting.
Base from your post look like a settings issues. I'm currently using Win7 on my machine so the setting may be set diffrently. If memory serves me right , Right click on your desktop and select properties. Choose the settings tab.Click on the external monitor 2 to highlight it, then check the box beside “Extend my windows desktop onto this monitor" and click OK. You may want to check "display" has been set to the correct graphics.