Mac mDNSResponder.plist error

Question

So, a friend of mine has been having trouble with his internet (skype is working, but browsers suddenly stopped working - both Safari and Firefox, and no access to the Apple app store). After trying advice from numerous threads from different forums, I tried giving him my com.apple.mDNSResponder.plist file, and he replaced his version without making a backup copy of his own (he's not a computer person, he misunderstood me...). So now, if I try to have him load/upload the file in Terminal via: sudo launchctl load /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist it says that there is 'nothing found to load'. I looked at the permissions for the file, and it seems right...but it seems like mDNSResponder isn't working at all, because when I had him type: sudo killall -HUP mDNSResponder it says 'no matching processes were found'

Anyone know how I can fix this?? (He's also in the middle of nowhere in Japan for the summer, so no access to startup disks, backups, etc - just me via skype)