Windows – Shortcut to set screen resolution

Nircmd is a nice command line utility that can help. It has an option to set screen resolution and even accepts options to set a specific monitor to a specific resolution.

If you read through the documentation then it appears you can create a command shortcut with Nircmd that you should then be able to modify to add a shortcut to. Look for the "cmdshortcut" command.

setdisplay {monitor:index/name} [width] [height] [color bits] {refresh rate} {-updatereg} {-allusers}

Changes your display settings. The [width] and [height] parameters represents the number of pixels on your screen. The [color bits] parameter represents the number of colors shown on your screen (8 - 256 color, 16 - 16bit color, 24 - 24bit color, and so on). {refresh rate} is an optional parameter that specifies the monitor refresh rate. If you specify the {-updatereg} parameter, the new settings will be saved in the Registry. If you specify both {-updatereg} and {-allusers} parameters, the new settings will be saved in the Registry for all users. If you have multiple monitors, you can use the optional monitor parameter, which specifies for which monitor you want to change the display settings. You can specify the monitor by index (0 for the first monitor, 1 for the second one, and so on) or by specifying a string in the system monitor name. The monitor name can be found in the Device manager of Windows: Right click on the monitor item, and then choose 'Properties'. The string displayed in the 'location' field is the monitor name.

Examples:
- nircmd setdisplay 800 600 24 -updatereg
- nircmd setdisplay 1024 768 24 90
- nircmd setdisplay 1024 768 8
- nircmd setdisplay monitor:1 1024 768 24 90
- nircmd setdisplay monitor:name1 1024 768 24 90

As far as my understanding goes, screen size is not important. It's rather the screen resolution that is important.

In the simplest (non-existent) case, each dot on the mouse's pad corresponds to one pixel on the screen. So, for example, if your screen resolution was 1920x1200 and your mouse was capable of a maximum DPI of 600, you'd have to move your mouse two inches to get from the bottom of the screen to the top. If your mouse used a DPI of 1200, it would only take one inch to make the same movement on the screen.

Therefore higher mouse DPI allows you to move faster on the screen with less mouse movement. Higher resolution displays may require higher sensitivity or higher mouse DPI to attain the same amount of on-screen movement, or one would need a ridiculously large mouse-pad.

Sensitivity is software based. It gets your dpi and divides or multiplies it to get the final dots-to-pixels sensitivity. It is just a multiplier of the input sent by the mouse. For example, if you had the mouse on 3600 DPI and then set the sensitivity to 2.5/10, it would function the same as 900 DPI on 10/10 sensitivity.

There are cases where mouse sensitivity in the supplied mouse driver is applied in addition to Windows mouse sensitivity, it all ending with an unpredictable mess.

So, for your questions:

Same DPI but lower resolution : Mouse will cover larger physical screen territory with the same hand-movement. It will be harder to click exactly on a specific small area on the screen.

Same DPI but higher resolution : Mouse will cover smaller physical screen territory with the same hand-movement. Working with small screen objects is easier as the mouse is "slower".

Same DPI, same resolution but different screen size : Getting from one side of the display to the other will take more mouse movement. But if the same windows are displayed in the same size, working inside such a window will be the same. For getting faster across a large screen, you could use mouse acceleration together with fast and large gestures. However, in gaming mouse acceleration can make you overshoot your target.

Both higher and lesser mouse DPI have their advantages. I am, for example, currently using a mouse that has a DPI switch button, so I can change the DPI to suite my current task.