I bought k350 keyboard and m510 mouse a while ago. Did not like the scrolling lags and erratic moves so I got a different brand chip corded one that I use for years. I have a new computer and wanted to use the Logitech devices. Came to find out that it is not just plug and play. In order to take advantage of the nice features you have to download software, install etc, etc, etc. I have tried for the past 3 days to make it work to no avail. I will never, ever, under any circumstances what so ever will purchase LOGITECH brand.