Cannot open connection Dialog when starting SQL Server Management Studio

I start SQL Server Management Studio on my workstation and get the following message.

TITLE: Microsoft SQL Server Management Studio

Failed to open connection dialog.

ADDITIONAL INFORMATION:

Could not load file or assembly 'SqlMgmt, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) (mscorlib)

BUTTONS:

OK

I had SQl Express version installed previously and everything worked. I could connect to one server running SQL Express and a different server running full up SQL 2005 enterprise version.

I uninstalled All SQL express programs and installed tools from SQL 2005 developer.

I have rebooted, started the program directly (not using a link of any kind) and all attempts fail. After dismissing the error msg the tool opens and I can run queries agains the DB but the database engines and related tables do not show.

My work station is Windows XP with SP2 installed.

I have googled the problem extensively and tried solutions found but none have solved the problem.

Any help greatly appreciated.

I uninstalled all SQL Server components, deleted all directories (there were no files) in the installation directory. Then reinstalled SQL Server 2005 developer edition. All management tools appear to work correctly.