Sysprep questions

Hello everyone,

I'm getting myself familiar with Sysprep and I'm using Zenworks 4.0.1 to
deploy the images to my new desktop computers and I just have a few
questions. First, I have a few computers in production that are acting
pretty weird on the network, and what I mean by weird is intermittently the
machine cannot login, but if you try again it can. Now this was before I
was aware of Sysprep and I was under the impression that Zenwork's imaging
agent did all what Sysprep did, apparently not. For the computers that I
did not sysprep, can I just re-sysprep those product desktops that I forgot
to sysprep without rendering the user's machine useless? By doing this, do
you think it might clear up the little weird quarks that are happening on
these newly unsysprep'd desktop computers?

Thank you for your help.

Alex Anderson