I assigned the bluetooth host controller to the guest and vista detected it. I installed the driver that boot camp is providing for my computer and for 32bit windows, which is broadcom 126.96.36.199 from 2011. The driver installs fine, but the device fails with code 43. I am stuck here. I can't find any different driver or see what the issue with the code 43 is. Any newer drivers I saw are large installers (>120MB) that fail installation when they can't detect the "bluetooth device".
The 188.8.131.52 driver I used can also be downloaded from the following page, note that none of the other downloads installs for me. https://www.driverscape.com/download/apple-broadcom-built-in-bluetooth