alright m8
First, on the PC create a user, "dreambox" and a password, then give this user the permissions to be able to write etc. to the folder you are sharing. Also any firewalls you may be using need to be altered to let the dreambox do what it needs to.
I don't have a 500c and I don't know what image you are using, but this is what I had to do for my 5620. In mounts select CIFS, make sure your IP of your computer is correct, mount it in HDD, don't put any /. infront of the share name ie "movie". Enter the user name and password you created on the PC. Tick automount. I had to name my shared folder movie, or it wouldn't record.
I left all other options as they are. nolock, intr, soft and udp. rsize=4096 wsize=4096
If you want to stream mp's to your dreambox from you pc, do the same, except, mount the share in mnt, not hdd.
Hope this helps
yoinker