Epson 486SX - Manual (Page 182)

Mouse Problems
If you are having a problem with your mouse or you see an
auxiliary device error message, check the following:
Make sure the mouse cable is securely connected to the
mouse port and not the keyboard port. The mouse port has
a special icon on the computer case. See Chapter 1.
If you installed a mouse on an option card, be sure to set
jumper JP7 to disable the built-in mouse and enable the
mouse on the card. See Chapter 6 for instructions.
If you control your mouse with the Microsoft mouse driver 7.0
and the cursor is not operating properly or freezes within a
program, you may need to install the MOUSE7PT.EXE
program. Follow the instructions below.
Using the MOUSE7PT.EXE Program
The MOUSE7PT.EXE program creates an additional mouse
driver which you can load for any program that has trouble
controlling the cursor. Your original mouse driver remains
unchanged.
Follow these steps to install and run MOUSE7PT.EXE:
1. Identify the disk and directory where the current
MOUSE.COM file is stored.
2. Insert your Reference diskette in drive A.
Troubleshooting B-27