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Help : "error: 40 - Could not open a connection to SQL Server" RRS feed

  • Question

  • I'm using VS2005 and SQL2000. I created a database name "myDatabase" in SQL Server 2000 and built a website that
    connet to this database. When I'm running this website in VS2005 IDE (press F5 or Ctrl-F5), everything is OK. I publiced
    this site. When I connect to database on my computer, everything is OK also, but when I connect to database on another
    computer, an error occurred like this :

    "An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005,
    this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections.
    (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2)"

    Now, I don't know how to fix it. Pls help me as soon as possible.
    Regards.

    Friday, November 25, 2005 2:56 AM

Answers

  • The error "error: 40 - Could not open a connection to SQL Server" istelf can be caused by several reasons.  The additional error code often helps to narrow down the problem. 

    For example, the original post lists this:

    "... (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2)"

    - error 40 is generated by the SqlClient provider, and is somehwat generic in this case. 

    - error 2 is the "winerror" that comes from the OS, and is more specific: ERROR_FILE_NOT_FOUND in this case (see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/randz/protocol/winerror_h__part_1.asp). 

    ERROR_FILE_NOT_FOUND most frequently indicates that the client attempted a connection to the *local* SQL Server but the server is either not available, not running, or not accepting connections.  One possibility is that the server was specified as ".", "(local)" (or ".\SQLEXPRESS", "(local)\SQLEXPRESS").  If a connection to a remote server is desired the actual name of the server must be used instead of ".". 

     

    With regard to connections to a default instance server that listens on a non-stadard TCP port: Client Network Utility cannot be used to configure the default target TCP port used by .Net Fraemwork 2.0 (or VS2005).  You either need to specify the port in the connection string, e.g. if the port is 1500 you can specify "targetServer,1500", or you can create an alias specifying the TCP port (here, Client Network Utility can be used). 

     

     

    Tuesday, February 21, 2006 11:53 PM

All replies

  • Hi - I am having the exact same problem.

    Thomas
    Wednesday, November 30, 2005 9:05 AM
  • Me too,

    After switching from Enterprise Manager to Management Studio I can no longer connect to remote databases (version 2000):

    An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (.Net SqlClient Data Provider)

    Update: Using MS Access 2000 I can still connect, by creating an "Access Database Project". Not really good enough, though.

    Wednesday, November 30, 2005 12:45 PM
  • Same problem here... I'm not sure what I changed, but I can't access my database anymore.
    Thursday, December 1, 2005 3:39 AM
  • Same sort of problem here.

    Installed VB.net 2003 alongside VB6 and now my vb6 programs cannot connect to remote servers. I use MSDE on my own computer with enterprise manager for access to the main server and my own computer and nor can enterprise manager connect anymore to remote servers.

    The only thing that has changed on my computer is the installation of VB.net 2003.
    Thursday, December 1, 2005 1:29 PM
  • Have some simular issues here too, totally random though.
    Thursday, December 1, 2005 8:33 PM
  • Same problem here.

    I'm using VB.net 2005 Express and Mysql Server Express.
    I'm connecting (for now) to a sql server on my same local machine as my vb.net.

    Anyone figure it out yet??
    Thursday, December 1, 2005 11:06 PM
  • I ended up reinstalling SQL Server and Visual Studio. Reinstalling SQL Server didn't help; reinstalling Visual Studio and SQL Server did. I don't know why.
    Friday, December 2, 2005 5:52 AM
  • Ok. Try this. Get the visual Basic 6 Runtime Files from Microsoft of wherever they reside.
    (I had a copy on my computer from a previous problem)

    Install them as normal, 2 min job, then try your connections again to remote servers.

    I did this and suddenly I was able to connect to remote servers again.

    vbrun60sp3 size 0.98mb is the file I used.

    It is available still if you put the file name in microsoft and search.

    WHAT I DONT KNOW IS IF I AM DOING ANY OTHER DAMAGE BY INSTALLING IT!

    I AM NEW TO VB.NET AND DONT KNOW ENOUGH TO TELL IF I HAVE BROKEN SOMETHING ELSE BY INSTALLING IT.

    Thanks.
    Friday, December 2, 2005 9:08 AM
  • Hi Havan,
           I'm having exactly the same problem. Please let me know if you know how to fix the connection problem with VB2005 and SQL Express. Thanks in advanced.

    DC
    Monday, December 19, 2005 5:51 PM
  • Same problem / error

    Laptop at work no problem connecting to remote sql server

    Same laptop at home could not connect to server

     ISP is blocking port 1433 to prevent sql worms

    Talked to ISP and they unblocked 1433,

    Be persistent with them!

    Use netstat -an to view open connections

    TCP              IP:random port       IP:1433        results

    before unblocking

    TCP    ???.???.???.???:1184     ???.???.???.???:1433   SYN_SENT

    After unblocking

     TCP    ???.???.???.???:1184     ???.???.???.???:1433   ESTABLISHED

    Thursday, December 22, 2005 10:12 PM
  • Hello,

    I was having this same problem.. I was trying to connect Visual Web Developer 2005 to the SQL Server Express 2005.

    My problem was:
    I was connecting to <machine name> as my server... after changing it to <machine name>\SQLExpress it started working fine. Hopefully this helps.

    anx
    Friday, December 23, 2005 2:46 PM
  • The above solution worked for me as well but my problem was that I was connecting to SQL 2000 where SQL 2005 was also installed. 

    The connection worked until I moved from app home to work locally on my XP System.  Our server only has SQL 2000 but my local machine has 2005 and 2000 running. 

    I suspect that there are more variations to this problem. 

    Pete

    www.sensibleprogamming.com

    West Coast of America

    Monday, January 2, 2006 12:51 AM
  • I have the same problem, but this didn't help for me.

    Can someone pleace give me an example how the connectionstring would look like, when connection to an shared sql server on another server.

    Wednesday, January 4, 2006 12:40 PM
  • This worked perfectly!  I was dreading having to do something like a re-install.
    Wednesday, January 4, 2006 4:34 PM
  •  

    My problem is also that I can connect at work, (behind a router) and not remote. This only happens with VS 2005 trying to connect to SQL 2000. VS 2003 connects just fine. My SQL Server is on a unique port and I changed this in the 'Client Network Utility' in SQL 2000, however it didnt work for 2005.

    I can not believe that we have not had a single MS person address this thread.

    Monday, February 20, 2006 6:27 PM
  • The error "error: 40 - Could not open a connection to SQL Server" istelf can be caused by several reasons.  The additional error code often helps to narrow down the problem. 

    For example, the original post lists this:

    "... (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2)"

    - error 40 is generated by the SqlClient provider, and is somehwat generic in this case. 

    - error 2 is the "winerror" that comes from the OS, and is more specific: ERROR_FILE_NOT_FOUND in this case (see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/randz/protocol/winerror_h__part_1.asp). 

    ERROR_FILE_NOT_FOUND most frequently indicates that the client attempted a connection to the *local* SQL Server but the server is either not available, not running, or not accepting connections.  One possibility is that the server was specified as ".", "(local)" (or ".\SQLEXPRESS", "(local)\SQLEXPRESS").  If a connection to a remote server is desired the actual name of the server must be used instead of ".". 

     

    With regard to connections to a default instance server that listens on a non-stadard TCP port: Client Network Utility cannot be used to configure the default target TCP port used by .Net Fraemwork 2.0 (or VS2005).  You either need to specify the port in the connection string, e.g. if the port is 1500 you can specify "targetServer,1500", or you can create an alias specifying the TCP port (here, Client Network Utility can be used). 

     

     

    Tuesday, February 21, 2006 11:53 PM
  • Hi, please excuse my poor english.

    Use SQL configuration manager, properties of Server Services (SQLEXPRESS), login: choose integrated account and choose local system.

    I had the same problem and the same error message - this helps

    Best regards, charly

    Friday, February 24, 2006 5:52 PM
  • One thing to note: Named Pipes does not work when configured as the only client connectivity option for ASP.NET running in default circumstances. Have a look at the following article:

    BUG: Named pipes do not work when worker process runs under ASPNET account
    http://support.microsoft.com/default.aspx?scid=kb;en-us;Q315159

    This is only an issue if you have disabled TCP/IP connections using the SQL Server Client Connectivity Manager
    Friday, March 24, 2006 6:09 AM
  • I wasn't connecting to SQL 2000 but after a clean install of SQL 2005 and install of SP1 I couldn't connect either.

    I'm using a domain account for my startup service account.

    I opened the SQL server configuration manager and discovered that TCP\IP was disabled. Once I enabled it, wah lah I have connectivity.

     

    Tuesday, June 13, 2006 8:30 PM
  • Thanks for this solution. After three hours messing around it solved my problem.
    Tuesday, November 7, 2006 5:05 PM
  • Hi,

    I had the same problem, but your solution worked!

    Thanks,
    Alex
    Friday, November 24, 2006 8:58 AM
  • I figured this out right away.  For all of you who are having the error:40 and Error:2 after installing Sql Server 2005, you may take a look at the Sql Server Service.  Although mine was not disabled, it was set to automatic but not started.  Once I started it, it worked like a charm.

    Hope this helps.

    Romel Evans

    Wednesday, November 29, 2006 8:52 AM
  • Try this if it is working ,inform me...thomas..

      First Step: Install SQL Server 2005 Ent edition in custom configuration to a windows server os.

    Second Step:Tick all tools menu in selection mode in your custom configuration installation.

    Third Step:Install SQL Server 2005 ent edition in default mode for your client systems.

    Fourth Step: Allow remote login in your server system for your sql users like(Right click my computer-properties- remote-select allow users remotely connect to this system-add the domain, sql users only. in services enable remote login and start service.

     

     

    Restart the server and try to connect thru remote from your client system....   thanks for doing this process..  

    Monday, July 2, 2007 11:33 AM
  • This soved my problem. I am a newbie to sql server can you or anyone explain the logic behind this.

    Thanks !

     

    Manoj

    Wednesday, December 26, 2007 6:58 AM
  •  

    installing vbrun60sp3.exe worked properly for me.Thanks
    Monday, January 7, 2008 12:23 PM