Don't bother to install the Logitech Mouseware driver. It will only do one thing for you, which is to configure the application change button, which is pretty useless anyway. If you must install it, do not use the CD version but the 975 version, which you can download from the manufacturer's site. This sorts the scrolling problem in games from which the previous version suffered. But if you use Windows XP, I strongly advise you not to use the Mouseware. On one test computer it did not work, and on another it crashed the registry and completely reinitialized Windows, in the process losing settings like the Azerty keyboard, the taskbar icons, etc. Fortunately, you can uninstall it and take an earlier restoration point. I don't know whether Microsoft is incapable of supplying Logitech with the requisite information or whether Logitech is incapable of programming for XP, but, whichever way, it's just not worth the risk.
The Value Of Simplicity
With its MX sensor, this little mouse is formidable in games. Its precision and response leave all the others standing. It fits in anywhere and into any hand and, for me, provides perfect comfort in gaming. If you find two buttons and a scroll wheel enough, then don't hesitate; this is the best mouse for games at an affordable price of 55 euros. It is strongly made and, in any case, an optical sensor does not wear out. You just need to clean the four nylon pads regularly with a damp cloth but nothing abrasive, which might scratch them. As soon as pads are dirty or scratched, the mouse loses a lot in precision and comfort.