The driver you need is "1394 OHCI Compliant Host Controller (Legacy)" This can be downloaded for free off the web.
I own 1) Sony DCR-TRV9E purchased 1999.
2) Sony DSR-PD175P Professional purchased 2010.
Laptop MSI GT83 Titan 8RG windows 10. This laptop does not have a firewire port so I used a Firewire 4-pin to usb cable. My other laptop does have a 4-pin firewire port. I had not used either camera for some time but both are working well. Recently I tried to download some film but the device was not recognised/unknown usb device/USB descriptor failure/usb problem (Code43).
I tried to update the driver to no avail. The footage exists as I can play it on the camcorder screen and tv. I need to edit it. I have used XP/Vista /W7 and W10.
Sony International could only suggest I send the camera to them to examine. I don't know what to do now; do I need a driver for the Firewire? Shouldn't it be integrated in the OS? Any advice welcome!