Unless the laptop is somehow connected to the desktop and the shock is causing a connection drop of some sort, I don't see any feasible way this could be related. There's no way a static discharge could affect something on a different outlet (or something at a distance for that matter). Even if you had some sort of floating ground, the charge is going to disperse rapidly and evenly along the floating ground and is only going to be a high potential difference (voltage) at the point of contact (finger and aluminum of the laptop).
EDIT: To clarify this a bit more, suppose you have a high potential difference in charge on your body from that of a piece of steel that is just sitting on a chair. When you touch the piece of steel, there is going to be high potential difference in voltage along the connected boundary of your skin and the steel. Why?
The reason is primarily related to the fact that there is only a small surface area for charged particles to disperse. Resistance is inversely proportional to contact area, so the smaller the area the large the resistance. And if you take into account that Current*Resistance=Voltage (IR=V) and Charge/time=Current (Q/t=I), you can see why there would be a large voltage in this case, because we have a large resistance and a quick dispersion of charge across the boundary or to say it another way: high current (I) and high resistance ( R ) is going to result in high Voltage (V).
Fortunately though, these conditions are only going be momentary and the charge is going to disperse rapidly across the boundary and evenly into the material with lower charge so even in the case of a floating ground in terms of something like a piece of steel, the high voltage is only going to be momentary at the boundary. If you had for example connected a large area of your body the metal, you would generate a proportionally lower voltage during the static electric discharge (perhaps not even a noticeable amount). The point I'm making here is though it sounds like huge numbers in terms of volts, it is something that is transient and only a result of the conditions that are present at the boundary. The reality that not much charge is really involved and that the large potential voltage and current won't last far behind the boundary simply because the charged particles will disperse evenly through floating ground after the boundary.