Can't change network properties. Says another sheet is already open

I've rebooted my computer, looked in Task Manager, etc. I
can't see where there are any other network property
sheets open. Yet when I try and open one (because I need
to change the DNS server) and it tells me I can't change
the properties because there are other network property
sheets open. Which there aren't.

I have been trying to get my network working properly with
Win2K server for a week. This seems to be a big key. I
need that DNS server setting changed.

Please help.

Thanks.

--Gabinka