hi,
as you have seen in previous posts, there are things that
you can lose and other no, it depends from which.
If your server is a AD domain controller, Gareth says, you
lose your AD data if you use sysprep (probably without
using nosidgen, it recreates sid and you lose AD info).
If you have just finished to install the server and you don't want lose your work and have a right copy ov WIN,
use sysprep -nosidgen (see doc) and go (after a backup, if
you can)
As above mentioned, I use sysprep to regenarate sid information and license-key, in servers just installed, to avoid to repeat my installation work. It works fine but
on servers there is only my work, not still user's data
or other.
If your server is in production from many months and/or
you have complex network or you think to sleep "bad" if
you lose user data (no sure of backup, no possibility
to stays with server off-line for some hours), hold your
server as is, I belive if you have the right number of licenses, you are from the right part of the law.
bye