If you do get a surge from lightning powering through the electrics, you won't be in any trouble if you have a new Surge-protected extension cord with multiple outlets because the extension cord will fry instead of your computer's power supply and various hardware. If your extension cord isn't protected or you haven't got any circuit breaker or surge-protection hardware built into your power supply, your computer and any other device that's plugged in will get utterly fried into various states of unusability.