I've had to use my computer a few times in the past without a mouse. Did you know you can use your keypad as a mouse? I didn't know if these options still existed in Windows or not. Apparently they do. If your mouse conks out on you here is a convenient quick fix.
Windows 10
In the search bar start typing Ease of Access. In the list then click on Ease of Access mouse settings. So first turn the feature on.
Then check whatever options you want. The first options makes it so Number Lock key has to be on first. The second just displays an icon in the task bar that basically tells you if it's active or not. The third will speed up the movement of the cursor, from experience, it is recommended.
Now by turning on the Number Lock key, on my system:
The number (8) moves the cursor up,
number (2) down.
(4) is left and
(6) is right.
(5), (+), and (./Del) keys are the same as right clicking.
The enter key would be the double click.
Windows 7
In the search bar start typing Ease of Access and click on Change how your keyboard works.
And click on Turn on Mouse Keys. You can change the mouse key options by clicking on the Set up Mouse Keys options in blue letters.Then OK.
Use the same keys as Windows 10 to move around. Except on Windows 7 The (./Del) key doesn't seem to do anything.