Your last question: should the styles be on Drive C if you are running the program from the PG Music supplied USB drive? No. The only thing that would be installed to drive C would be a few behind-the-scenes files such as Fonts.

It does sound like you may have run several installs and at least one had the wrong drive assignments. One of these could be from the update. Each update must be told where the files are (which can all be on the USB drive, which is fine).

Before you do a fresh uninstall/reinstall, I suggest you review this answer with PG Music Support. See the Support tab, above. They can even remote connect and look over your installation.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.