I'm having a bizarre problem that has only crept up today.

Although I've been connecting to the same server for months without incident, starting this morning I cannot connect to MS SQL Server via Enterprise Manager. It just happened "out of the blue"; no settings were changed or tampered with. I did install Adobe Creative Suite CS2 yesterday afternoon, but I was able to connect to the SQL server successfully for about a half hour before the problems started. No other software has been installed other than that.

Whenever I attempt to connect, Enterprise Manager freezes up for about 30-45 seconds and then responds with this message:

A connection could not be established to XXXX
Reason: SQLServer does not exist or access denied
ConnectionOpen (Connect())..
Please verify SQL Server is running and check your SQL Server registration properties (by right-clicking on the
XXXX node) and try again.

I know SQL Server is running, because the web apps that uses it works fine.

I've tried to connect via Enterprise Manager from other PCs at my work, and they are able to connect fine with the same exact settings.

I've since uninstalled and re-installed Enterprise Manager twice, deleted and re-inserted the server settings, all to no avail.:(

Has anybody heard of any similar incidents? Could it be an IP blockage of some sort?

Have you applied Active Directory recently on your network? We did and started experiencing similar problems. As I understand it, some servers outside of our local domain could no longer be referenced without using a fully qualified machine name.