The Paint application automatically saves the window size, position, and canvas size before closing.
Please follow this procedure to retrieve the default Paint window size and position, and the canvas size:
Go to HKEY_CURRENT_USER > Software > Microsoft > Windows > CurrentVersion > Applets > Paint > View.
In the right pane, you can see:
You need to delete all the above. Here’s how to do it:
Select these keys and then right-click on them.
Click the Delete option. In the confirmation window, click Yes.