Changing Command Execute Timeout in Management Studio:
Click on Tools -> Options
Select Query Execution from tree on left side and enter command timeout in "Execute Timeout" control.
Changing 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.