Machine shutting down

Hello,

I just purchased a new laptop - Dell. It is running windows vista 64 bit. When I am on the internet it just shutdowns. I bring it back up and get the screen that windows did not shutdown properly - do I want to bring up in safe mode or regular - I pick regualr.

It does not happen when I play my bridge game - seems to only be internet. I am using Comcast service with a Netgear G router which I installed. The netgear does not support the Vista 63 bit operating system but do not think that should be a problem..

Any and all help appreciated.