Why does the error message "Mouse is not connected" appear at the startup of my computer?

The following error message appear at the startup of my computer and both the mouse and the touch pad cannot be used. Why is that so?

"Mouse is not connected to the computer. Connect a serial mouse. Turn off the computer before you connect it to the PS/2 mouse port."

The error message appears because the driver of the mouse is not normally recognized.

The procedure below may resolve the problem sometimes.
* If your VAIO is a notebook computer, start the procedure from step 2.

--Procedure--
1) Turn off the computer and connect/disconnect the PS2/mouse.

2) If the above step does not resolve the problem, disconnect the mouse and initialize the BIOS settings.

3) If initializing the BIOS settings does not solve the problem, delete the driver of the mouse completely before you initialize the BIOS settings. Then, install the driver of the PS/2 mouse again.

4) If the above steps do not solve the problem, connect another PC/2 mouse to your desktop computer and see if the same problem occurs.

--Note--
When a PC/2 mouse is connected to a notebook computer, the problem is sometimes caused by the failure of normally recognizing the driver of the touch pad.

--Remarks--
If the error message appears even after the execution of recovery and if the PS/2 mouse or the touch pad is not usable, the problem may be caused by the hardware.

Please refer to the following solution in the Microsoft technical support website for more information.

Article ID: Q206002
Last Reviewed: October 20, 2000
Title: USB Keyboard or Mouse Does Not Work in Windows 98.
Link: http://support.microsoft.com/support/kb/articles/Q206/0/02.ASP