On Windows, if you want to open 4D Client when you double-click any access path file you need to do the following:

• On your machine, select any window.
  
• Select Options from the View menu.
  
• In the Options dialog, click the File types tab control.
  
• From the Registered file type list, select Client Connection.
  
• Below the Actions area, click New.
  
• In the New action dialog, type open as the action and select 4D Client application as the "Application used to perform action".
  
  
  
  
• Click OK.
  
• In the Edit File Type dialog, click OK.
  
  
  
• In the Options dialog, click OK.
  

If you then double-click any Access path file to launch your 4d Client application with that file's settings.