I'm confused...you're changing resolutions on the laptop's LCD, or you are sending the video out to a real monitor?
If LCD, then as gcraw said, stick with the native resolution of the LCD. By design, LCDs have one RGB crystal for each pixel. If you change the resolution in Windows, then that is no longer true and the pixels become interpolated. Your image is therefore degraded.
If monitor, then just set the resolution as high as the onboard video will output that still results in good frame rates. Personally, I don't see any benefit in games above 1280x1024. Higher resolutions don't add polygons to the models, and I notice that more than anything else these days.
XBox Live: Vulcan Draggon Steam: Vulcan Dragon
[B]Currently Playing: Metro: Last Night (X360), Minecraft Story Mode (PC), Fallout 4 VR (Vive)
Mafia II (Xbox 360)
Updated June 21, 2019