Updating the bios won't permit you to use windows 7. If windows 7 can find device drivers for your board, it will do so without the bios flash. The bios flash only effects hardware on the board, not software. If it can't find the lan driver, use an old lan card, which has a generic driver. If the lan is connected and you can get online, then let windows 7 search for updates. If it can't find the proper driver, then you'll have to settle for partial drivers. The board is too old.