Microsoft's new Mouse Button Lock lets you keep dragging or selecting after you release the mouse button. It arrives in PowerToys 0.102, released October 21, and gives you a way to separate moving the pointer from keeping a finger pressed down.
That's the useful reason to look at this update. If a long selection is awkward because you have to maintain the press, a different interaction may help more than another shortcut. You still control where the pointer goes; this isn't an automated selection tool.
Enable the button you actually use
Microsoft's mouse-utilities guide says the feature is off initially. Enable Mouse Button Lock in PowerToys Settings, then choose the buttons you want it to affect. Only the right button is selected by default; left and middle are options.
Hold the chosen button with the mouse still, release it, then move to drag or select. Pressing any mouse button ends the lock. The default hold is 1.2 seconds. Moving farther than five pixels during that hold instead produces a normal drag. Both thresholds are adjustable.
Those settings make a practice run worthwhile. Use a disposable document or a harmless selection first, rather than learning the release behavior while moving important files. In particular, notice the pause before moving: immediately dragging out of habit isn't the same gesture.
Windows already includes ClickLock for the primary button. If left-button selection is your only concern, consider that built-in option before installing another utility.
Check your app before relying on it
There are limits: Mouse Button Lock doesn't work over on-screen keyboards and needs matching elevation to affect administrator-level apps. That last restriction isn't a reason to give PowerToys elevated privileges routinely.
For an everyday workflow, the better question is whether it behaves predictably in the application you actually use. Try starting, extending and ending a selection there. A feature that sounds useful on paper still needs to fit your habits.
The release also adds ZoomIt screenshot dictation with on-device transcription and tap-alone keyboard remaps that preserve a key's normal combinations. You don't need to change all those habits at once to get value from the mouse setting.
Existing users can check for updates in PowerToys Settings. For a new installation, Microsoft's installation instructions recommend GitHub or the Microsoft Store. The stable release linked above is version 0.102.2933.0.
Start with the button you need, learn how to release the lock, and leave the other options alone until you have a reason to change them.