Hi sushiman: The lighting storm hit a near by power line sending electricity to all direction. You are lucky that it did not burn up your computer. Now that you have up and running again run a check disc. This scans your whole computer and will automatically fix files and drives that may have been dump or damaged caused by the power failer and surged. To prevent this from happening again buy a power surge protector cost any where from $7.00 to $20.00 and plug your computer and any other electrical stuff such as TV's and printers. That way the surged protector will trip out. Save you $1,000.00 s in replacing high dollar appliances. It is cheeper to purchased a damaged surged protector then a new computer.

Electrical power issues and surges are by definition unpredictable, it's just one of those things that happens, I wouldn't spend a lot of time trying to figure out the hows and whys of the symptom.

I would be sure my systems were on a UPS or brand name surge protector as Fred suggests, personally I prefer a UPS.