Should you turn off your computer during a thunderstorm? The question is certainly interesting. The first impulse was to write: “Yes, definitely." But let’s think about it. What if the job is urgent? What if the download of the desired file has not yet ended? What if … Yes, there are few such “what if”? So, before answering unequivocally, let’s figure out, firstly, what the thunderstorm actually threatens us with. The answer is simple – voltage drop. More specifically, the voltage drop during a lightning strike. We will not dwell on the physics of the process in detail, we will simply clarify that during a lightning strike on a copper wire, the secondary winding of the transformer may work. That is, over the cable, the discharge may well reach your PC and, to put it mildly, ruin it. And here we have a few "traitors". Well, first of all, it is the electrical network. The fact is that when a lightning strikes, the machines that should turn off the network, they simply do not have time to work and then everything burns, regardless of whether this device is working or turned off. The main thing is that the plug is in the socket. Hence the main rule, if you want to stay with a live computer, during a thunderstorm you need to unplug it from the outlet. That is, if you have a laptop, then please work calmly, but on a battery, and not from the mains.
It is also not recommended to leave the computer connected to the local network (this also applies to cable modems, since they work on the principle of a local network). After all, the principle of operation in the event of a lightning strike into the cable (or close enough to it) will be approximately the same as in the case of a voltage drop in the electrical network.
Thus, in order to protect your computer in a thunderstorm, it is better to unplug it and unplug the power cord.
A little easier if you use an uninterruptible power supply, in which case you have an additional stabilizer that can and will protect you from the negative effects of a thunderstorm. But this protection is very, very unreliable. If lightning strikes directly into the network, then no uninterruptible power supply will save you. Therefore, in my deep conviction, it is not worth the risk. In the end, if you delay work for half an hour, then no one will die from this, but if you lose your computer and all the developments like it, this is really a tragedy. And therefore, a simple conclusion suggests itself. During a thunderstorm, turn off the computer from the outlet, unplug the power cord and admire the raging elements.