When we try to change an existing table in SQL Server 2008, you might receive a Save (Not Permitted Dialog) box pop-up. This behavior is by default and happens under the following conditions: such as adding a new column to the middle of the table, dropping a column, changing column nullability or changing the data type of a column.
When we click the cancel button we receive another dialog as in the following:
To add a column to turn off the "Saving changes not permitted" dialog box, so that you don't have to recreate a table in order to save changes to the table, follow these SQL Server 2008 configuration instructions:
On the Tools menu, click Options.
When we click on the option, the option window will be displayed:
In the Options pop-up box select designers.
Uncheck the check box of the option that prevents saving changes that require the table to be re-created: