Windows 7 Network config

Hi

Have 2 macs with the same config of parallels everything is set up the same (both running windows 7 ultimate x64), however in the windows network configuration on one it says it has internet access shared from the airport of the macbook and on the other it has no internet access displayed. is there any possible reason why when both are basiclly installed and no settings changed, one has internet access and the other doesnt. happy to provide any information that is required thanks everyone.