Do you have FSX Deluxe/Professional/Gold, Marvin? If so, I think the SDK installer is on disk 1. Yes, you will need to install the SDK for ADE (or, I believe, Instant Scenery) to work properly. You'll then need to download the SP1 SDK (and the SP2 SDK if you're using standalone SP2) from Microsoft and install the Acceleration SDK off the disk if you're using that. It's a right faff, unfortunately, as you have to install them all in turn and they all uninstall each other before installing again! If anyone else knows a way around that, please let me know!
If you don't have the SDK (i.e. you have FSX "Standard" or whatever they called it), you can't use ADE, certainly, and will need to check whether you can use Instant Scenery from the website.
On the other topic, it sounds like my issues with decompiling might be to do with the fact that I was using an earlier version of BGL2XML - although why it would decompile everything perfectly well except IS files I'm not even going to try and answer. I used it on MS, ADE, FSXPlanner and SDE BGLs happily - it only fell over on Instant Scenery files, repeatedly.
Very odd!
If you don't have the SDK (i.e. you have FSX "Standard" or whatever they called it), you can't use ADE, certainly, and will need to check whether you can use Instant Scenery from the website.
On the other topic, it sounds like my issues with decompiling might be to do with the fact that I was using an earlier version of BGL2XML - although why it would decompile everything perfectly well except IS files I'm not even going to try and answer. I used it on MS, ADE, FSXPlanner and SDE BGLs happily - it only fell over on Instant Scenery files, repeatedly.
Very odd!