Open Older Captivate Files...

Consider this...Cp2 was the first version of Captivate I used. I first used it in 2005 (I think). That means that that project file could be up to 14 years old. Can there really be any content that needs to be brought forward in 2018? Even if you could work out a workflow for this, I would strongly discourage it for not just the technical reasons but from a perspective that you would need to conduct a full needs analysis on this material after that much time has passed (unless it contains your Grandma's recipe for apple pie).

Seriously? No, I don't think that is possible at all.  For most versions it is possible to open up to two versions back. You should need to convert more than once: maybe to 4 to start with, see if this delivers some result. With CP5 a big change in UI and features occurrec, maybe try to open the CP4 file in 5 but know that AS2 is no longer allowed in CP5 and that you have to check before upgrading. With CP6 lot of changes: themes were added which made the design base totally different.

Honestly I would prefer to recreate the projects in CP7 because I fear that it will take more hours to fix an update than to recreate.