Here's how to disable the recent documents history:

1. Type regedit in the Start/Run window.

2. Navigate to HCU\Software\Microsoft\Windows\ CurrentVersion\Policies\Explorer.

3. Create a new DWORD value, or modify the existing value of NoRecentDocsHistory by double clicking.

4. Set the Data Value to 1. Save the value and close the registry editor.

The next time you start Windows, your recent documents folder would remain empty and won't track your open documents.