So I was trying to find my mac address, so I followed these random steps, and installed a new IONetworkingFamily.kext without backing up the old one. So, yeah, I know that's now how you find out your Mac Address now. More importantly, my internet doesn't work now, and I feel like it's because I need a new .kext. Now the only thing I can think of is reformatting, but I have a ton of stuff on my computer.. It's 10.5.5, late 2008 Macbook Pro. Anyone have any idea on how I can go about fixing it?