BEWARE: if you have any of the following motherboards you will need to update your drivers and firmware for this product or it will cause problems with your computer
€ Intel 865P Chipset
€ Intel 865PE Chipset
€ NVIDIA nForce4 Ultra Chipset
€ NVIDIA nForce 680i Chipset
€ NVIDIA nForce 650i Chipset
€ Intel P965 Express Chipset,
€ Intel P965 Northbridge, i82801HR Southbridge
I have two of these now and they have both broke. First one broke because it was working fine at first and didnt realise to update drivers.
Second one broke because it would not allow me to install new firmware so i gave up and it eventully (longer then last time) broke again.
Apart from these problems. Very comfortable and stylish. The very best mouse for fans of Guild wars.