Timeless Time & Expense Enterprise Web can be used with the Windows version of Timeless Time & Expense Enterprise. However, it cannot use MS Access as a database option.
If you are using MS Access, you must first install one of the other database options and convert your database. Reinstall Timeless Time & Expense Enterprise Windows, selecting the new database. Be sure all clients are connecting to the new database.
Finally, install Timeless Time & Expense Enterprise Web, selecting the same database as Timeless Time & Expense Enterprise Windows.