No network drive after SP2 upgrade.

Hello,

Can somebody give some hints to solve the following problem:

At this moment I am trying to deploy XP SP2 using WSUS, the upgrade works
fine with this tooling (if you don't use SSL in WSUS in combination with AD)
the only problem I have is the client, after installation XP SP2 all network
drives are gone, this problem is solved after the first reboot.
The problem for me is the time between installation SP2 and the first reboot
initiated by the user.
Does anyone know a solution for this problem, sending a mail to my customers
if they could initiate a reboot does NOT work.