An unhandled exception may occur when you try to connect to an Access database from an ASP.NET worker process

When you need unlimited users, full-time support, and ACID transactions, Microsoft strongly recommends that you use Microsoft SQL Server with Microsoft Internet Information Services (IIS). Although Microsoft Active Server Pages (ASP) works with any OLE DB-compliant or ODBC-compliant database, IIS has been extensively tested. IIS is designed to work with Microsoft SQL Server on high transaction traffic and with unlimited users, which can occur in an Internet scenario.

Note "ACID" is an acronym for the four properties of transaction-processing systems: Atomicity, Consistency, Isolation, Durability.

ASP supports the use of the Microsoft Jet database engine as a valid data source. However, Microsoft ODBC Driver for Access and Microsoft OLE DB Provider for Jet are not intended for use with high-stress, high-concurrency, full-time server applications (such as Web applications, commerce applications, transactional applications, messaging servers, and so on).

Steps to reproduce the behavior

1. Create a new ASP.NET Web Application project in Microsoft Visual C# .NET.
2. Add the following code to the "Declaration" section of your Web Form, which appears at the top of the Code window:

   using System.Data.OleDb;

3. Add the following code to the Page_Load event:

       String myConn  ="Provider=Microsoft.JET.OLEDB.4.0;Data Source=C:\\Nwind.mdb;";
       String myQuery  = "Insert into Customers(CustomerID,CompanyName) Values ('aaaaa', 'aaaaa')";
   
       OleDbConnection cn = new OleDbConnection(myConn);
       cn.Open();
       OleDbCommand cmd = new OleDbCommand(myQuery, cn);
       cmd.ExecuteNonQuery();
       cn.close();
   

4. Modify the connection string as appropriate for your environment.
5. Compile the project.
6. View WebForm1.aspx in your browser. Notice that you receive one of the above-mentioned exceptions.