How can I remove a non-existing server name from the dropdown list when starting SQL Server.

I have recently changed the machine name, for reasons not associcted with SQL Server. Now, when starting SQL Server 2008, in the "Connect to Server" dialog box, the "Server name" dropdown box offers two server name choices in addition to the <browse for more...>. One of these is the present machine name and the other is the old machine name. I understand that when I installed SQL Server, the default name of the server (instance) is the machine name of the host computer.
Of course, if someone tries to connect to the old server name, it fails to connect and gives an error message. I would like to remove the old server name from the dropdown list to avoid confusion.
If I go to the menu and choose View/Registered Servers/Local Servers Groups, the old server name is not shown. Since it isn't registered, it can't be deleted. Executing sp_dropserver doesn't get rid of the old server name either.
This seems to be a bug (although not serious) in SQL Server 2008. I can live with the inconvience, but if someone has an solution, I would appreciate some help.

I believe it is cached information in your registry...try to reboot and see what happens..
Search the registry with server name...

Thanks for your reply.
I rebooted, looked in the registry, then removed and reinstalled SQL Server. The old machine/server name is still there.
If I select "browse" from the dropdown list, and then select the present machine/server name, the name gets added to the dropdown list as a duplicate selection.
If there is a clean fix, I'll try it. Otherwise, I'll live with it.
Sure looks like a bug to me.
Thanks again, Gary

I have the same problem as Gary. Once a named instance has been registered, it appears you are stuck with it. Even if you uninstall everything, reboot and reinstall.