I've recently installed Norton Utilities 15 on my MacBook Pro (it has both MacOS10 and Windows 7 installed); I set Utilities (I think) to do a disc check at boot up and now the computer won't boot up (in Windows) - it starts a Norton disc check and then says there is a problem and tries to fix it but it can't; I've tried starting in Safe Mode but it hangs part way through. HELP