For the most part nobody’s done much of anything with Firewire on Windows for more than a decade, so pretty much any card you get is going to be an ancient card using an ancient chipset.
In addition to that challenge, Windows 10 more or less forced a driver system on us where Windows will “phone home” to find the right drivers for a device that’s installed in a Windows 10 system. Usually this works great, but sometimes it’s horrible. A case in point where it is horrible is with firewire drivers.
There are two major firewire chipset providers: Texas Instruments and VIA. Within both of those you have multiple generations and multiple categories of firewire chips. Certain firewire devices are known not to play well with certain chipsets. I believe firewire audio in general, and RME specifically, has been reported to have problems with the TI X102200A chipset. With that case aside, many people said they had better luck with the TI chipsets than VIA chipsets.
Back to windows driver issues - some chipsets simply don’t work well with the drivers Windows 10 automatically downloads and installs. And by “don’t work well” I mean the unpredictable “stopped working” and “blue screen” type errors. So it wouldn’t surprise me at all if your card just doesn’t like the drivers Windows installed.
If you know the specific card you have you may still be able to get the old “legacy” drivers that were made for windows 8 or windows 7 or whatever the current windows was when the card was new.
If you do manage to identify the card and locate the drivers, there’s a process to go through to force windows 10 to use the “legacy” driver that actually work and stop using the Windows driver that it thinks is the right one.
Last time I went through all this was 2018 and it was a few hours of Google searching to find 10 year old conversations on scattered forums, then rolling the dice on what I thought was my best bet. It works for me, but it’s not made anymore, so I can’t exactly recommend it.
Probably the most useful advice I could give is:
look at the card that’s in your system now. Chances are the card isn’t the problem. It’s more likely the driver. Look at the main chip on the card and it will say either VIA in big letters, or it’ll have a picture of Texas on it. Look at the numbers on it, Google for it, and see if people say it needs “legacy drivers.” If you don’t know what you’re looking at, take a picture of it and post it here.
if you end up buying a new card, get a firewire 1394a card. You don’t benefit from the extra speed of 1394b unless you plan on daisy chaining a few audio interfaces together. A lot of cards have both. (1394a is firewire 400, 1394b is firewire 800). More people seemed to report more problems using 800 than 400 with Windows.
make sure any card you’re looking at will actually fit in an available slot on your PC. Basically, you have either the small PCIe slots, or the older and longer PCI slots. Chances are you want a PCIe card, with the small slot. Unless you’re on a 10 year old PC, then you probably have the long slots.
The difference is obvious when you look at the part or the card that inserts into the slot on your motherboard.