Hmm, I had the exact opposite experience than nin-ha. I had many problems when installing setpoint from disc, especially when it came to updates and the like. Every time I started setpoint I had to re-associate my mouse to the software. My recommendation is to uninstall setpoint completely, then visit logitech support >> http://www.logitech.com/en-us/support
Follow the instructions in option 4 or download the auto-detect function in option 1. Then install the latest version for your mouse. Good luck.