Problem creating computer-to-computer network

Hi All,

About 3 months back i bought the latest 21.5 inch iMac, every thing works fine except that it does not allow me to create a adhoc network ( computer-to-computer network ), i had been a windows user all my life therefore i am not sure if there is an alternative way to create this kind of a network…

i click on network and then click on create a network, channel i leave it automatic and when i click on create network i get the error message ” There was an Error creating computer-to-computer network ”

plz help..

— Sufi