You have to make sure that file and printer sharing is enables on both systems
to do that in vista go to sharing center and turn on sharing
in xp from folder options - view - allow simple file sharing
then create a folder
in either machines
right click it
and click share
enable sharing on the folder
now make sure you know the computer name
go to the vista machine
computer name is your computer name shared folder is the name of the folder you created
vista by default '(when sharing is enabled) will allow any thing in the public folder to be shaed on the network
make sure both computers are on the same subnet and netwrork
Step 1:get the ip address of both the computers
make sure they are in the same work group and has different computer name.
step 2:make sure they are able to ping each other , if not disable the firewall
step 3:share the drive or the folder that you wants to share in vista, by right clicking on it and click on properties and allow permission for everyone.
step 4:type in the shared name
step 5:you can disable password protected in vista computer.
step 6:from the xp computer go to network->view work group computers and click on the vista computer , you should be able to see the shared folder or drive.