I want to edit a form that was created in ArcPad 7. I do not have ArcPad studio. Can I upgrade to ArcPad 8 or 10 (ArcPad Studio bundled) or do I need to purchase ArcPad Studio 7 separately to edit the form?
Just upgrade to the newest version, 10.2. You'll be able to edit your forms (I assume .apl files) just fine. Those forms can then be integrated very easily into the axf file format.