Go to the Windows Menu (Start button)
Find "Computer" in the list and right-click on it.
Choose "Manage" from the dropdown.
Select Device Manager from the left side.
Right-click on the entry for the IEEE bus host controller and select "Update Driver Software".
In the window that appears, click "Browse my computer for driver software".
In the next window click "Let me pick from a list of device drivers on my computer".
In the next window you will see a list of drivers, one of which says "1394 OHCI Compliant Host Controller (Legacy)".
Select it and click "Next". Windows will then install the legacy driver.
*NOTE For Windows 8, 8.1, 10 the "Legacy" driver is not available to select. You will need to download it from here
After this you need you need to run the same fix as Microsoft describes below in Micosoft KB article 927827 "Windows Vista does not enumerate an IEEE 1394a device that you connect to the computer"
Either you can follow the link below in the Microsoft article or us our fix for this which can be downloaded here
Download the file.
Extract the ZIP file.
Run the executable file.
Windows Vista - will not detect P 21, P 30 and P 45