Thank you very much Craig.

But I'm still a little at a loss to understand why on the same PC I do have access to the corporate sql servers on the lan in VS2012 and not in VS2010, i.e in the "Choose Data Store" dialog in VS2012 it shows me sqlservers that it does not VS2010.

Thanks for caring.

>It has nothing to do with the Express VS SKUs and everything to do with the EDITION of SQL Server you installed and how it's configured.
>
>There is a "local database" that is essentially a version that only allows local connections. You give a filename in the connection string and your application attaches to it.
>Then there's SQL Express that does allow for remote connections. BUT, you can configure it to not allow remote connections or only allow certain protocols to connect (for example, named pipes or TCP/IP) . Look for SQL Server Configuration Manager on the box to see how it's configured.
>
>
>>One of my uncountable blind spots is sql server client and connections, but this seems to be a resilient one. :)
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>>If I get this right, in .net express 2010 you have limited access, i.e. you can only connect to a "local" sql server, i.e. one that is not located on another server in the network.
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>>Now in net express 2012 I can see all the sql servers that are running on the company's LAN. So (1) is that a change in policy by Microsoft, or is this me having installed my .net 2010 wrongly, and (2) can I still connect to non "local sqlserver" via odbc or oledb ?
>>
>>Thank you so much for any light you could shed on this ...