MYSTERY NETWORK ITEM OSX
If you see Rac_Pc available in your network list when using Apple OSX, it is likely because you are also using a
router and there is a Nintendo Wii system also using the router via wireless.
This observation is based upon my own equipment observations.
WINDOWS USERS: I am not familiar with Windows, but I suspect you could be seeing the same thing across your network using a similar configuration of CPU/Wii/Router