Can't Create Databases In Management Studio

I seem to be having a number of problems using managment studio (MS) against my locally installed SQL 2005 Standard Edition. E.g. when I create a default database using MS it says...



TITLE: Microsoft SQL Server Management Studio
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Failed to retrieve data for this request. (Microsoft.SqlServer.SmoEnum)

For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&LinkId=20476

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ADDITIONAL INFORMATION:

An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)

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The server could not load DCOM. (Microsoft SQL Server, Error: 7404)

For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=09.00.1399&EvtSrc=MSSQLServer&EvtID=7404&LinkId=20476



However, the hyperlinks are less than helpful. I also get problems doing various maintance work from MS. I don't think its a database engine problem 'cause I can do all the work via TSQL DDL but the interface is so much easier to use (or should be). BTW it's running on XP Pro (firewall problem?).