This is a sample of the registry file I am currently using, taken from the below KB.
Windows Registry Editor Version 5.00
This will allow the XP SP2 to refresh DFS without hitting the F5 key.
The other solution is to put in the login.bat file this code. But it this does not work use the first resolution on each workstation as admin.
I make this change on all deployments of DFS.
The way that I get the registry change to the users is with the following command in a login script. Login scripts run under a different context to the user account and therefore registry changes can take affect.
%systemroot%\regedit /s dfsrefresh.reg