IIS5 - ODBC - Data source name not found and no default driver specified

I’ve got some problem using an ODBC connection with IIS.

Here is my config :

• IIS 5 on Windows XP
• ASP.NET 2.0
• Oracle 9
• VS 2005

When I try too use my web application on IIS, I’ve got the following exception:

ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

BUT, when I use it like a web site in VS2005, I didn’t have any error.

So, I’d try to make a very little app, with the following code:

using System;
using System.Data;
using System.Data.Odbc;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        OdbcConnection con = new OdbcConnection();
        con.ConnectionString = "DSN=<MyDSN>;Uid=<LOGIN>;Pwd=<PASSWORD>";

        IDbCommand com = new OdbcCommand();
        com.CommandText = "select sysdate from dual;";
        com.CommandType = CommandType.Text;
        com.CommandTimeout = 30;
        com.Connection = con;

        try
        {
            con.Open();
            Response.Write(com.ExecuteScalar());
        }
        finally
        {
            if (con.State == ConnectionState.Open)
                con.Close();
        }
    }
}

It work fine on VS’s web server (ie: http://localhost:3715/Web/Default.aspx), but I’ve got the same exception (IM002) when I use it on IIS (ie: http://localhost/Tester/default.aspx).

My DSN is declared on the “ODBC Data Source Administrator” and work well when I test the connection…

The ASPNET account is in the same group as my user account (Administrators).

Full right for ASPNET Account on HKEY_LOCAL_MACHINE\SOFTWARE\ODBC and HKEY_CURRENT_USER\Software\odbc keys.

I've read this post, but nothing work...

I'd look after an answer on stackoverflow (search, related questions, etc.), google...but I didn't found a working solution...

Is there anyone who have an idea?...

Where is my mistake?...

UPDATE: 2011/04/06

What I’ve done so far:

• Tracing for ODBC: on VS’Web server, I got log; but on IIS, none...
• System and User DSN are filled with the same information
• Allow ASPNET, IUSR_XXX, IWAN_XXX, and all users (sic…) accounts full rights to: %ORACLE_HOME%, HKEY_LOCAL_MACHINE\SOFTWARE\ODBC, HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE

Windows, VS and IIS are all for 32 bits (so, there is no c:\windows\syswow64).

Check PATH value, and put %ORACLE_HOME% first.

IIS was reset each time I do a modification, my computer reboot twice.

But, now, I’ve got this message:

ERROR [IM003] Specified driver could not be loaded due to system error 998 (Oracle dans OraHome92).

And I finally found... The administrators have install all the drivers in order to be used by the user only...

I’d create a system env var ORACLE_HOME...

The开发者_运维技巧re was only a user var :s

Thanks for your help.

I validate the Garry M. Biggs' answer because of the difference between system/user...

Had this problem ..
The best solution is to re install your odbc driver ... worked for me ..
the registry entries in your system might have got tampered .

I did a complete uninstall and re install .. worked for me .. lame but quick solution .

Make sure you have created a System DSN rather than a User DSN.

IIS will be running as a System service and therefore does not have access to User registry entries...

1. Maybe your system is 64 bit version of Windows and IIS is 64 bit, but VS is 32 bit? If so, look at my answers: odbc connection string dosen't work on windows 7

2. If you can connect from one environment and not from the other then enable ODBC tracing and compare log files. MS described it at: http://support.microsoft.com/kb/274551