Can you tell which wifi chipset it is using. Guess it depends on how old windows is. It generally will tell you the chipset name it reads in the device managers. Kinda how it know if you have the correct driver.
I don't think you can actually flash the card, maybe on those really old ones you could. Generally the key functionality is built in when it is manufactured. This was done to prevent for example changing the country code and running on illegal radio bands. The old cards you could do that.
I don't know if the WPA version is a hardware feature that is built into the chip or it is loaded via the software driver. The driver for the OS has a binary "file?" inside it that it loads into the wifi chip. This is basically the OS from the wifi chip. It generally comes from the chipset vendor.
Your best option is to try to find the chipset and then go to the chipset vendor site and look for a driver. Problem is a couple of the very big wifi chipset makers were bought by others and you can no longer find any of this old drivers...at least on a offical site. They still exist on those sketchy sites that you never really know what you are downloading.