Am I correct in assuming that you are aware from my previous posts that I have BIAB2018 and RTs etc on my laptop's D drive and you want me to copy and install to C to avoid "contamination" ?
Good point, I should have said D. Actually I was just trying to provide clear simple instructions for getting a full BB2018 onto your laptop. Yes by all means if BB is on your D drive and you want it there, that's completely fine. You can even have more than one Band-in-a-Box folder on your hard drive.
Let's say you have D:\bb as your Band-in-a-Box folder, and for the sake of argument you have your full bb folder on a portable hard drive. I would (1) rename D:\bb to D:\bb_old for the time being as a backup (you could just delete it, but why not just rename it until you're finished? Or you could copy over top of D:\bb, but then you have to answer questions from Windows about overwriting files and merging folders). (2) Next you could copy the full bb folder to D:\bb. That will take some time, so be sure not to disturb the hard drive connection. (3) Finally you could install BB2018 into D:\bb. There are a number of ways you could do this, but one way is to run the original 2018 installers, and install to D:\bb.
FYI, the alternate .txt file is normal, and it is just using audio from a different folder. The .ST2's in question use audio content from specific RealTracks folders that you don't have. It seemed from your original post that you were ONLY missing the simple bass st2 files, and that made sense to me because they were released later than the original basses. However apparently you are missing the audio content as well. Instead of trying to figure out why this is the case and if you are missing other things in the new folder, I came to the conclusion it was best just to copy your entire folder over and then you're done.