BassRocket
But on the safe side, what folders should I transfer to my external drive for safe keeping, in case of blunders?
The advice about de-activating your plugin licenses in advance is a good one. Have heard many stories of pain involved for those who forgot to do this.
In addition, it is always a good idea to back up your Cakewalk Projects folder, your user folder (My Documents, etc.), and any folders that your plugins keep their custom settings and presets in.
That last one can be a challenge, because all developers seem to think differently about how to do this, and there is no standard. You may have to research each one yourself. To be safe, you could easily just make a copy of your current system drive onto a separate drive, for reference after the migration. That way you can just drag and drop anything that you are missing.
I always take a system image before making any changes, and that has always worked fine as an archive for future reference. Just mount the image as a drive (varies with image software, but most allow this), and drag and drop files/folders from it as needed.
And make sure that you have all of your application software and plugin installers (and serial numbers) on hand.
Good luck!