"Subform in New Window" is grayed out (Access 2003) (1 Viewer)

I hope this is an easy one that someone can help me with. The command "Subform in New Window" is grayed out. I am using MS Access 2003. I added a subform to my existing project. I am in Design View (of course), I select the subform, it has its handles around it. And the command is grayed out.

I created a NEW empty project/database. Created a form, added a subform to it. And it (the "Subform in New Window" command) is STILL grayed out.

I've tried this on one PC with MS Access 2003 and on a second PC with MS Access XP. Same on both.

Google search didn't yeild any good hits.

I think what has happened is you have created a subform window on your form, however the subform window is not linked to any particular form. The command "Subform in New Window" will work once you have linked the subform window to an actual form.

You may find it easier to approach it in this way. Instead of creating a subform window on your form, just drag the form you wish to appear as a sub form and MS Access will start a wizard that will help you marry the two forms together.