The user instance of SQL Server could not be built because of an error while initiating the process of the user instance. The connection will be closed.

This is an error I encountered when I was using the visual Studio 2008 development platform. This error is an error that occurs when you add a connection in Server Explorer and load a database file.

What the heck??? I was wondering, I have never seen such a wonderful problem before? It's been a smooth pass, huh? I baidu a bit, online some say, what what "login Super admin Delete local/appdata/.... Bla bla bla ... folder, restart on it can be "what, I spent half a day to do, hair with no matter." I do not know is my character owes, or this trick is not very good, and then let a large pile of people directly copied past.

Well, self-reliant, clothed. The following begins the analysis. First of all, I was using the WIN10 system, vs is version 2008, and the database is the VS Companion 2005 Express Edition.

I carefully recalled the passing of my error, and found that I had a detail in the process of the previous operation, that is, I copied a copy of the project to another folder, and by the way also copied the database past a copy.

In fact, the problem is here, is not a serious problem, this error is precisely in a very basic point-the right.

The database was created by me before the database was copied, so the permissions are here for me and are duly completed. But after I manually copy the file, the permissions will be very difficult for me-the fact is, click on the properties, click on the "Security" tab, point to their own users, see the following permissions, presumably everything is understood-this file, I do not control its permissions. Changed it. Try again, too.

Summary: When you see the above error, if the previous manual copy of the database file, you need to modify the MDF and LDF two file attributes, the control rights for the appropriation, can be normal connection, perfect as ever.

Incidentally, sometimes when you add a connection, the data source selects Microsoft SQL Server, and the database file is loaded with a problem:

1, this may be in the database when the logical name of the problem, try to remove the logical name left blank and try again;

2, it is also possible because the database physical file MDF file and log file LDF does not match the content, try to change the data source, select "Microsoft SQL Server database File", directly load the MDF file, test the connection.

The user instance of SQL Server could not be built because of an error while initiating the process of the user instance. The connection will be closed.