Sure there is - The upgrade path is to sell the old card (Craigslist or eBay, etc) and buy a new PCIe card :-) Or keep the Hammerfall for use in an older PC (still runs under W7-32) as a complete backup DAW if your "up time" is worth money...
Of course, you could always run W7-32 on your new PC and live with the RAM limitations w/o spending a dime - or at least to tide you over until you can secure a new card.
PS - There is a used Multiface + PCI card up on eBay for $450. I have no clue who the seller is, but the price is right. While still PCI based (and somewhat of a limitation for the latest LGA1155 PC's that dropped native PCI support) - Being a member of the HDSP family - it gladly runs under W7-64. It does look like an older card (v1.3) - so that might be a concern.
http://www.ebay.com/itm/RME-Audio-Multi … 27c1ad9db9
(this auction is not affiliated with me in ANY WAY!!!)
I also saw another one listed for $550. Not cheap, but cheaper than buying a brand-new PCIe card just to get W7-64 support...
MADIface-XT+ARC / 3x HDSP MADI / ADI648
2x SSL Alphalink MADI AX
2x Multiface / 2x Digiface /2x ADI8