When you installed the client, did you install it as a Service? That is the only way it could possible affect the boot sequence. If it is truly the cause of your boot problems, check the Event Viewer to see what errors are showing. If it isn't clear, post the error info here, and let us have a look. I have used DNETC in many versions (final and beta) in Win2K (final and beta) and never had similar problems.