To amplify Gary's post, this is what I recommend:
Step 1: if you are upgrading from before 2.6.9, screen shot your settings, uninstall everything, reinstall 2.6.9 from the
official release, redo your settings manually. Otherwise, if you've already got 2.6.9 skip to Step 2.
Step 2: if you want to experiment with 2.7.0, make a backup of your settings by exporting your database file just in case you need to go back to Step 1. Then download Richie's latest dropbox link from the
official 2.7.0 topic and copy/paste those files over the top of what you've got in C:\Program Files (x86)\OpenHPSDR\Thetis
Advanced methodology:
Make a backup copy of C:\Program Files (x86)\OpenHPSDR\Thetis
Make a backup copy of C:\Users\<your username goes here>\AppData\Roaming\OpenHPSDR\Thetis
Make your changes. See if you like them. If you don't, delete the two directories named above and rename (or copy) the backup directories back to their original names as given above.
You can keep as many versions on your hard drive like this as you like.