The WiMax Driver in an additional driver for your Intel Centrino Wireless-N + WiMax card. The driver for the wireless networking will still function fine for connecting to wireless routers and browser the web, etc... The WiMax portion is for using WiDi or Wireless Display functions in conjunction with an adapter you can purchase such as the Netgear WiDi adapter... It connects to your TV or other display and allows you to wirelessly display your desktop or extended display on a TV without physically connecting wires, such as HDMI, etc...
If you do not use this function, you can just ignore the error. But, there is an update for Windows 7/8 on the Intel site to install this driver if you'd like the error to go away...