Am going to install PSE 15, but have PSE 11 and PSE 5 already installed. When installing '11' I adopted '5' s catalogue ( and perhaps more info?) so I didn't lose anything. Now if I want to delete '5' after installing '15' (due to space on my hard drive ) would I lose parts, or more of my catalogue?
Additional question - as I have many 'missing files' would it be better to delete everything and start anew?
Deleting earlier versions will not have any impact on your catalogs. You can simply convert your older version catalog in PSE15
Regarding missing files, you can reconnect them through instructions mentioned in the article Photoshop Elements (PSE) knowledge base.
If you have done some organization of your media files, deleting them and starting afresh will result in doing all that work together.
Therefore, it is better to get those files reconnected. If you have not done much work with those files, then you can delete them as well.
Thanks for the information Anwesha.