I've upgraded Biab2015 pro to Biab2018 UltraPak. Because I updated from 2015 to 2018 therefore there are many STL and st2 files still left on the BB folder. Can I delete these files ?

That's a good question we haven't run into yet.

I think the answer is going to be to run the cleanup utility again. It's just an .EXE in the /BB/Data folder. But I suggest calling PG Music Support if you have any hesitation or wait for further answers since everything should work as it is for now.

Looks like I was correct. I did some research and found a comment by Peter Gannon about just this issue:

The old installers will put many files in BB folder. Then the user should manually run the cleanup routine again. Either run the bb_cleanup.exe from the bb\data folder or from the help-utilities- menu in BB

They also plan further modifications to make this easier in the future.

Thanks Matt Finley for your info of search and help.

Glad to help. Your question and this thread will be useful for others.

After run the bb_cleanup.exe from the bb\data folder, the BB folder is now clean, the files were moved to their proper folder

Excellent. Thanks for reporting that.

HELP: I just ran the Disk Cleanup, so where are all my RT Demo Folders go???. Now just one shows. See screenshot.

Is there an undo??

Could they be in:

x:\bb\Demos\RealTracks - Demos\

Thank you for that info. Yes they are there.
That single Folder, should I just move it or should I run the Clean up again.

You could run Cleanup again; it can’t do any harm. In fact, running old installers will put files in the old folder structure and you have to run Cleanup again.

Thanks guys for the responses.