I figured it out how to use 4.20.01(T) with my Dell Bluetooth 350.
1. Download the 4.20.01(T) bluetooth stack from
http://aps.toshiba-tro.de/bluetooth/...s&download=3ww
2. Run the installer. Tell it to ignore the Windows driver warnings. After a while, it will tell you to press Fn+F2 to turn on the Bluetooth card. Even if your wireless functions are on, it will keep prompting you. So go ahead and cancel out of the installation.
3. Reboot
4. Go to your device manager (right click on My Computer->Properties, select the Hardware tab, press Device Manager). (Or Start menu->Run->devmgmt.msc)
5. In the Universal Serial Bus Controllers list there should be one that is marked by a yellow warning triangle. Double click it. It'll say that the device driver isn't installed. Keep this window open for a bit, you'll need it later.
5.9 Backup C:\WINDOWS\inf\tosrfusb.inf in case you mess it up in the next step. Not that it'll do you much good now anyway.
6. Edit C:\WINDOWS\inf\tosrfusb.inf in Notepad or equiv. Where it says Rfusb_DellDevice (%TosrfUsb.DeviceDesc87%=Rfusb_DellDevice, USB\VID_413C&PID_8120) replace that with "%TosrfUsb.DeviceDesc87%=TosrfUsb_Device, USB\VID_413C&PID_8103". (no quotes) Find all instances of "8120" and replace them with "8103".
7. Save the file.
8. You might need to trash tosrfusb.pnf. Maybe.
9. Go back to that device window you opened earlier. Click the Install Driver button. Let it search automatically. It'll find two matches. Pick the second one ("Dell Bluetooth USB adapter").
10. There might be some other associated "fake" devices that the Toshiba stack will ask you install after installing the driver. Let it install them. Hopefully things work. If you don't have a blue antenna icon in your systray, you might need to reboot.
Moo.