this is more of an Windows-administration question.
to set up a default profile, you'll need to use
-the policy editor (poledit)
-enable enable roaming profiles
-save a config.pol file (using poledit) in the netlogon share on sme
poledit comes with each windows-version somewhere in the admin/tools directory on the Window$ installation cdrom.
very carefully RTFMs on poledit and roaming profiles, search the m$ knowledge base on this, as uncarefully use might even lock you out from performing administrative tasks.
good luck,
Bart.