I'd had a Sony DCR-TRV22E MiniDV camcorder for several years. It was always recognised by XP without the need for installing any seperate drivers.
However, I've now tried it with both XP and Windows 7, and it's not recognised. When plugged in via a Firewire (iLink) cable, nothing happens at all. When plugged in via USB, it's considered an unknown device.