Networkin problem

i am using vista home on laptop and xp on desktop and want to make a network. but vista system appears on other but could not be opened and message appears permission required. On the other hand xp system is not shown in network on vista laptop. pl guide

Check mark in share option to allow all user full access including alter/modify than it will be usable. I dont know much about networking but solved problem with this and vista or xp did not asked user name and password again.