My internet is broken suddenly.?

I somewhat agree with Ashley. There's a good chance that something was damaged when the power supply went out. If you haven't done so already, try installing the network card in a different PCI slot, as the current slot might have been effected by the power supply. If that doesn't work, you might want to consider a wireless router with a USB receiver. USB is a completely different way of getting internet access to your computer, which might byp the damaged circuits. Hope this helps.