Did this device come pre-installed in your computer at the time of purchase or did you purchase it separately then add it to the computer?
I wasn't aware that Marvell made pci network cards, so are you sure about a PCI interface or could it be actually a chip integrated on the motherboard or possible a laptop pci mini card?
Is it a LAN (wired) or WLAN (wireless) card?
Used in a laptop or desktop computer?
Motherboard/Computer brand and model?
Did it come from the factory with Win7 x64 installed?
Can you provide the hardware id string found in Device Manager, double-click the device then click the details tab. Copy the first line of text to notepad, then paste it here in a post.
Check this thread: http://forums.driverguide.com/showthread.php?t=58291
I doubt Windows 7 x64 drivers exist unless the machine came from the factory with that OS installed.