I don't know. The netbook needs to be able to handle the higher input properly. Think of the human body. A mild shock the body can resist but ramp that up to sticking your finger in an outlet or getting struck by lightning and your body cannot overcome the extra power since you weren't designed to handle that much.
The netbooks input specs need to be checked to see how much input it can handle.
A long time ago I accidentally set my adjustable power block to 4.5v rather than 3v for a tape player, the player was fine, but after a while a part of the case got soft, I unplugged it and the player worked fine, but I almost certainly decreased the lifespan.
Mind you a tape player, even the fancier ones with auto reverse and a radio built in are likely far more resilient with incorrect voltage than a laptop would be.