Vista Tutorial - Network discovery desn't work on my private network

The computer I'm having problems with is running vista ultimate.

I have 2 network connections on my computer, one is my Internet connection
which I've selected as a public network and the other one is a wireless
network connection which I've selected as private in the Network and Sharing
Center.

I've looked on a few websites and they say that if you have a network
connection marked as private network discovery should be turned on
automatically for that network. However when I click on start, then network,
in the network window it tells me "network discovery is turned off". Then if
I click on it to change the settings all it does is give me an option to
either make the connection I'm connected to a private network or turn
network discovery and file sharing for all public networks.

I've turned off the firewall to the wireless connection in windows firewall
settings and it doesn't help.

Any help would be much appreciated