Hey there! This error typically means that you are trying to establish a connection to a database but the system can’t locate the Data Source Name (DSN) you provided, or your system is not finding the default driver specified.

Here’s how you can fix this issue:

1. First off, check out your connection string. Make sure the DSN you’re specifying matches exactly with the one you have configured in your system.

2. If you’re using a 64-bit machine, there could be a slight hitch; the drivers installed should match your system architecture. If you’ve a 64-bit application, you need a 64-bit driver. And vice-versa for 32-bit. Make sure you’re using the right one.

3. If you’ve mentioned a driver in your connection string, confirm that it’s installed on your machine. Sometimes, the driver may not be installed or the installed driver could be outdated. If so, try installing/updating your database driver.

4. Lastly, the issue could also be with the Driver Manager. To be precise, your system might have both 32-bit and 64-bit Driver Managers. If the wrong one is being used, you may encounter this error. As a solution, you could specify the full path to the correct driver in your connection string.

Hope this helps!