What is .HTB file extension?
Help file used by Audacity, a free sound editing program; stores a compressed archive of Windows help files, .HTML files, and images; used for displaying help information when selecting Help ? Contents in Audacity.
HTB files are stored in a .ZIP format. Therefore, you can rename their extension to ".zip" and decompress them with any ZIP decompression utility.
You can see a list of software programs here on easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.