Both of these mice are Microsoft compatible, they require the built in Microsoft driver that comes with Windows to work. That is not a problem with desktop systems, since you only need to change the driver to the Microsoft Mouse, which would then change / overwrite the one the computer is using. However, most laptops have a built in pointing device which shares the PS/2 port with an external mouse, and man have their own driver in order to make the built in pointing device work. If it isn't the Microsoft mouse driver, it may be a driver that isn't compatible with these mice. Even the Standard PS/2 mouse driver, which is what a lot of laptop use, is not the same. You do not want to change the driver that the laptop use, since it could disable the built in pointing device. Rather, you want to add these mice as a second pointing device, and need to plug them into the Serial port instead. As long as you are running Windows 95 / 98 / NT Workstation 4, the operating system will support two pointing devices on different ports. To add the second pointing device, go into "Control Panel - Add New Hardware" and pick the Microsoft Serial Mouse driver to be added. If the laptop wants to restart the operating system, you need to let it, so the second driver can be added. If nothing is interfering with the serial port, once the laptop restarts, these mice will now be working. The most common reasons they do not work are even when following steps, is because there is something else is using the serial port inside the laptop such as a modem or palm pilot. It also could be that the port is not enabled. You want to check the manual which came with the laptop to see if the serial port was shipped out with it disabled and how to enable it if necessary. Another reason we have found is that in some cases the port does not give off a strong enough signal to communicate with the pointing device. Docking stations and port replicator can cause this problem. Another option is to look under the pointing device and check to see if it has a switch and set it to the opposite of what it currently is, but do this when you are not within Windows. If it is done within Windows it will lock up the system