Why does the mouse pointer move by itself or the cursor moves to unintended locations ?

Why does the mouse pointer move even in the situation when the mouse is not controlled ?

Or

Why does the cursor move to the location that was not selected by the pointer ?

Check the problem according to the procedures listed below:

1) If you have installed other manufacturer's USB mouse driver or software that changes the cursor settings, the mouse may not move correctly. Therefore, check to see if you have installed a mouse related driver or software.

2) The pointer (mouse cursor) may move by itself when the pointing stick is not used under the normal operating condition. This symptom is called "drift" and it is not a failure.
Remove your fingers from the stick for a while, and the pointer will stop moving.
In addition, check if your hand on the palm rest touches or is pressing the arrow keys as the left arrow key, especially, can be pressed easily.

3) Check the sensitivity of the pointing stick.
Click [Start]->[Settings]->[Control Panel] and double-click on [Stick]. On the [Sensitivity] tab, make sure the slider of "Stick Sensitivity" is located midway between "Heavy" and "Light." If the slider is not in the middle, adjust the slider to the middle. Click [OK] to close the Stick Properties dialog box.

4) The cap for the pointing stick may be set incorrectly. Make sure the cap is not tilted.
*A malfunction may occur if it is tilted.

5) If the cursor is still moving after trying out all of the above, turn off the power of the system and power on again. When the power is turned on, the stick is initialized.

6) If the cursor is still moving after the system has started, contact VAIO customer link.