Have you tried to run browse the internet using Netscape Navigator to browse the internet after 2010? It's doable, but it's far from efficient -- in fact, most websites are completely deformed from Netscape's browser point of view because of the numerous improvements that programming has seen (HTML5 in 2014, for instance)
The funny thing is that, Netscape's latest update wasn't that long ago -- it was in 2008. In a mere 8 years, Netscape has been rendered nearly impossible to use.
The same applies to hardware technology. If the laptop was perfectly maintained and the damage of time were to be ignored, the odds are 'WiFi' and 'Bluetooth' would be stuffs of the past. Likewise, battery chargers, even power outlets might look different in 300 years from now on - perhaps they'll be wireless, something that is not compatible on a 300 years old laptop.
USB slot might not have the same shape, perhaps we'll be at USB Type Z version 44 by then, so most of the new technology would be incompatible with the 300 years old technology. It might not even be possible to find a compatible charger for the laptop!
But assuming that there was already an OS installed, it might work with what is already installed on it, but there probably won't be any internet, or any slot compatible with the newest technology.
Of course, that is if we ignore the fact that in 300 years old, most of the hardware would've been completely impossible to use due to the fearsome power of destruction also known as time.