hey,
this happened to me once, what I did what type in the MAC address of the card (that is if its network/LAN applicable) into Google, this gave me the original manufacturers location. In my case it was Taiwan, I explained to the person that I lost the software, he put me in touch with someone in my location and they emailed me the software. Hope that helps, so yeah try typing the MAC address of the card.
Have you tried contacting the manufacturer?
I can't post the contact page, because I'm new to these forums. But there is a telephone number on there, I would give them a call and see if they'll email you the software.
Good Luck.