I also use an older PC with a firewire connection and have Corel Video Studeo Pro X6 to load my MiniDV tapes to a EXTERNAL HARD DRIVE.
Then I move the HD over to my editing machine (Screamingly fast Lenovo Erazer). I use VS, Pinnacle and Vegas Pro on the Lenovo depending on what I want to do. It handles everything from 4K down to the MiniDV video.
Hope this helps,