You didn't tell us if this is a retail or OEM board. If it's a retail board, please visit the MSI website. If it's an OEM board, please visit the website of the company who used it to build their computer system, ie: HP, Compaq, Gateway, Dell, eMachines, etc.
If you want us to find a driver for you, please include answers to those questions above. Or..... provide the hardware id string for this device (found in Device Manager). eg: double-click the network device, click the Details tab, give me the 1st. line of text. It should start with PCI\VEN