Please do the following checks to verify the cause of thisproblem:

1. In Control Panel -> System -> DeviceManager -> Network Adapters, check the adapter status. If theadapter has Question mark or Yellow ´ ! ´ mark,this means the driver has not loaded properly, try re-installingthe driver. You can right click and select properties, selectdriver tab and update driver.
or
2. In Control Panel -> Network -> TCP/IP,select Properties -> IP Address, make sure the IP addresssetting and subnet mask are in the same range as your other workingcomputers.