Please tell some more about your configuration to be able to get an idea what is the root cause of your problems:
1. do you have an internal disk in your mede8er, if yes is it formatted from mede8er menu?
2. what kind of network setup do you have (wifi, fixed lan cable, which router or switch) and how are things connected?
3. is connection from your PC to the internal disk possible (if you have one installed)?
4. did you setup your shared folders on your PC with a guest account of other account?
5. did you try to use the registry hacks as described here http://www.mede8erforum.com/index.php?topic=64.0
6. did you try to reset your network (unpower your network router/switch, mede8er, pc, etc) and start up again.
Without giving as much details as possible, it will be really difficult to find out what is giving you this problems.