Their are several reason for timeout error, can you check what you have configured in your
SQL Server for timeout!!
Also check what is connection timeout option you have define in your connection string,
and if you are accesing it from SSMS go to
Tools->options->Query Execution->
Select Query Execution from tree on left side and enter command timeout in "Execute Timeout" control

change the value of Command Timeout in Server:
In the object browser tree right click on the server which give you timeout and select "Properties" from context menu.
Now in "Server Properties -....." dialog click on "Connections" page in "Select a Page" list (on left side). On the right side you will get property
Remote query timeout (in seconds, 0 = no timeout):
[up/down control]
you can set the value in up/down control.

SQL Server for timeout!!
Also check what is connection timeout option you have define in your connection string,
and if you are accesing it from SSMS go to
Tools->options->Query Execution->
Select Query Execution from tree on left side and enter command timeout in "Execute Timeout" control

change the value of Command Timeout in Server:
In the object browser tree right click on the server which give you timeout and select "Properties" from context menu.
Now in "Server Properties -....." dialog click on "Connections" page in "Select a Page" list (on left side). On the right side you will get property
Remote query timeout (in seconds, 0 = no timeout):
[up/down control]
you can set the value in up/down control.
