The problem is likely to be a defective product. Before contacting Logitech Technical Support, please check the following.

Your mouse can be connected into either a USB port or a PS/2 port. Please select your connection method below:

• PS/2 port
• USB port

PS/2 port

If you are using a PS/2 port:

1. Your PS/2 cable may be connected to the PS/2 mouse port on your computer, not the keyboard port. The PS/2 ports are shown below:

   PS/2 Keyboard port	PS/2 Mouse port

2. If your MK100 mouse is connected to the wrong PS/2 port, do the following:

   1. Turn off your computer. This is important - PS2 devices cannot be hot-swapped.

   2. Swap the cable to the correct port.

   3. Turn your computer back on.

3. Make sure that your PS/2 cable is firmly and securely connected to your computer.

USB port

If you are using a USB port:

1. Make sure that your mouse is plugged securely and directly into a USB port on your computer. KVMs and hubs are not supported.

2. Try plugging your mouse into a different USB port.

Additional Information:

If the above solutions do not resolve your problem, consult Knowledge Base article 24932 for instructions on contacting Logitech Technical Support.