I've browsing the forum a bit and I see that some people are using WinXP SP3 on ZDM7. But I can't quite make out if this combi is officially supported by Novell. Also, the document "Updates to Novell ZENworks 7 Desktop Management" (TID3484245) doesn't specifically mention WinXP SP1.

This must be one of the easier ones for you to answer, Shaun. :-)