If your ASP.NET site shows errors such as “The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine” or “The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine,” the server either does not have those OLE DB providers installed or the bitness of the provider does not match the application pool. On shared Windows hosting you normally cannot install or change system providers. The most reliable workaround is to use ODBC with a DSN and connect through System.Data.Odbc rather than OLE DB.
In your Plesk panel, start by creating an ODBC DSN for the Excel file. Sign in to Plesk, open your site, and go to ODBC Data Sources. Add a new DSN and choose the Excel driver that matches your file type. Name the DSN and, when asked for the database path (DBQ), enter the full absolute path on the server, for example E:\vhosts\yourdomain.com\httpdocs\DBfolder\yourfile.xls. Confirm that the site’s application pool identity can read that path. Save the DSN.
In your ASP.NET application, reference the DSN in web.config and specify System.Data.Odbc as the provider name. A minimal example looks like this:
<configuration><connectionStrings><add name="Excel1_ConString"connectionString="DSN=Excel1_ConString;"providerName="System.Data.Odbc" /></connectionStrings></configuration>
In code, open the DSN with OdbcConnection and query the worksheet. Do not use OleDbConnection when you connect via ODBC. A simple pattern is:
using System.Data.Odbc;
string cs = System.Configuration.ConfigurationManager.ConnectionStrings["Excel1_ConString"].ConnectionString;
using (var conn = new OdbcConnection(cs)){conn.Open();using (var cmd = new OdbcCommand("SELECT * FROM [Sheet1$]", conn))using (var rdr = cmd.ExecuteReader()){while (rdr.Read()){// handle row data}}}
If the site reports “An OLE DB Provider was not specified in the ConnectionString. An example would be, 'Provider=SQLOLEDB;'” while you are using providerName="System.Data.Odbc", the connection string is mixing styles. Remove any Provider= clause and keep it as DSN=YourDsnName; and make sure your code uses OdbcConnection. If the DSN cannot find the file, replace relative web paths with the full server path and verify the file actually exists. If permissions errors appear, grant the site’s application pool identity read access to the folder and file. If your environment only exposes an .xls-capable driver and you are uploading .xlsx, consider saving the workbook as .xls.
Some environments allow DSN-less ODBC connection strings. If the correct driver is present, you can define a direct connection string in web.config like this:
<add name="ExcelDirect"connectionString="Driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)};DBQ=E:\vhosts\yourdomain.com\httpdocs\DBfolder\yourfile.xlsx;"providerName="System.Data.Odbc" />
Excel files are convenient for uploads but they are not a database engine. For production use, consider importing the data into SQL Server or MySQL. Keep worksheet names simple, avoid special characters, and copy uploads to a working folder before reading to reduce file locking. If you follow the ODBC DSN approach with the correct provider name, full file paths, and appropriate permissions, the “provider not registered” errors go away without requiring server-wide OLE DB installs.
