Update on this.
Since my last post the situation is the same. After a long time the wireless laptop eventually picks up the desktop on the network. So I did a system restore. Checked ipconfig and stats are the same as previous. At least I can access the desktop, so I'll accept that for now.
I have looked at other forums about media dfisconnected, and this does seem to be a widespread problem.
This is one that I looked at. http://www.anetforums.com/posts.aspx?ThreadIndex=28415
---------- Post added at 11:40 ---------- Previous post was at 11:08 ----------
The Netgear router has software V1.0.11_1.0.1VGUK.
Is the latest version?