Originally Posted By: Bob Calver
...i'm trying to put off buying a new pc as long as possible.


There's nothing to stop you putting BiaB on an additional disc, whether USB or internal. For USB, you'll likely need a USB 3.x port on the PC (the ones with the blue tab inside).

Adding a disc inside a desktop machine is usually pretty easy.

Laptops can be less easy, but...
I have a fairly old ASUS notepad that was feeling slow and had pretty much run out of disc space. I replaced the old disc with a new 1TB Samsung EVO SSD, which has breathed a huge amount of new life into the old dog. (It was the notepad I was using when I bought BiaB 2013; dual-core Celeron IIRC).

Jazz relative beginner, starting at a much older age than was helpful.
Kawai MP6, Korg M50, Ui24R, Saffire Pro 40.
AVL:MXE Linux; Windows 11; Win8.1: Scarletts
BIAB2022 UltraPAK, Reaper, a bunch of stuff.