CAUTION: A common practice with Virtual Servers is to create one and then simply make duplicate copies and rename them. However, renaming a system does not make it unique, because the original System ID that is generated is the same for each copy. This is bad news when joining
a domain, because systems can be registered with duplicate SIDs causing all sorts of network oddities and problems. To fix this, you can use the NewSid utility to create a unique ID on the VS before joining a domain or installing Active Directory. The NewSid utility is available for download here:
Be aware, however, that sometimes even when NewSid is used, WSS and MOSS installations can fail. In production, I recommend creating each Virtual Server from scratch.