silly me - deleted settings in Host-Guest

Help!
While sorting out a problem with built-in Ethernet, I managed to delete the ip address, (and maybe something else too) in the Parallels Host-Guest tab.

Can someone please explain how to restore these settings? I'm sure this has got to be easy, but I really am just a clueless end user.

Oh, and as a result of these lost settings, XP is not able to share files with OSX - very sad indeed.

Thanks in advance for your help!