Fetching of list failed (no replies)

I'm trying to migrate an MS-SQLServer DataBase to MySQL using
"MySQL Migration Toolkit" v1.1.17 (final?)
But when I try to obtain the DataBases list I have the following response:
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Fetching of list failed
Unknown server host name "PC\SQLEXPRESS"
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I have copied the name from the login box in "Microsoft SQL Server Management Studio Express" where the connection was successfull
I have also tried the following host names:
SQLEXPRESS
localhost

With the later (localhost), the response is the following:
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Fetching of list failed
Network error IOException: Connection refused: connect
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INFO:
MS-SQLServer, MySQL server and MySQL Migration Toolkit are in the same Computer (local)
Software:
OS: Windows Vista Home basic SP2
DBMS: MS-SQLServer 2005 Express

Please, can someone give advise on how to succeed the connection?