Could boot up problem be motherboard?

Hello, I have a Sony Vaio laptop model VGN NW20EF. It powers on but does not connect to operating system Windows 7 and just goes to a blue screen with a few leaves and a white bird and no command buttons. I am trying to run the windows startup repair from a disc but it has been running for over two days now - it shows a grey box with 'startup repair is checking your system for problems' and 'attempting repairs'. The hard drive worked when put into another computer. Could it be the motherboard and if so is there anything i can do to fix this or does anyone recognise these symptoms and can advise please? Thanks