"The Microsoft Jet database engine cannot open the file. It is already opened exclusively by another user..."
The account that is accessing the page doesn't have sufficient permissions to lock the database. The account would be either the anonymous account (by default the IUSR_computername) or a specific user account if the page has been secured for authenticated access.
If you are using an Access file, it may not have proper permissions. To check the permissions:
- Find the database file in File Explorer.
- Right-click and select properties.
- Select the Security tab and click the Permissions button.
- In the File Permissions dialog, make sure "Everyone" appears in the list box with Full Control as the access type setting.
Another cause for this error may be due to the fact that the Microsoft Access file you are attempting to connect to is locked and a lock file (.ldb) exists. If this is the case, search for any *.ldb files and delete them. If another DSN (user or System) exists which is accessing the database, you may want to delete it as well and ensure that a single DSN refers to the database. Reboot the machine after making these changes.