Informatica Workflow Cannot create proper Relational connection object to connect to SQL Server

On my Infa server PC, in Informatica Administration I created a repository service giving Oracle Database information. Once in Informatica I connect to this repository and there I want to create a mapping importing a table from a remote sql server pc (on my home network domain) and then create a workflow to put the data into an oracle target table. Using ODBC admin console I created and tested the connection and I am also able to telnet the linked sql server and port. Within informatica I created a relational connection for sql server and when I run the workflow I get the error reason (14007) failed to create and inituiate OLE DB instance and datatabase driven error, failed to connect to database using user I use in SSMS for windows authentication and connection string(). I would like to know, first of of all, if I am doing something wrong, willing to connect me to a repository with oracle database information and then use a sql server table on remote pc. Do I have to create another repository for Sql server and there use sql server tables or I can mix them? secondly I would like to know how to create a relational connection object in informatica for my linked sql server so that it will be the same of relatonal connection created with ODBC admin consolle. Last but not least I would like to understand why gives an error out saying I left connection string empty, when I cannot see a place where I can put it by creating the relational connection object