[Tsiklon]

The extension cable they used to include in box with the computers, it has the third pin for the charger brick connector which is wired to ground

[15155]

There's zero chance that the DC ground in the laptop is tied to earth ground in the charger: they use LLC resonant converters and flyback converters (depending on vintage) - an earth ground tie would defeat the purpose of these isolated topologies.

[jahnu]

However it’s wired up the fact is the electric buzzing feeling goes away if you use a grounded extension cable instead of two pin.

[namibj]

No they isolate L and N not PE.