Currently Being ModeratedFeb 4, 2013 8:33 PM (in response to Amorific)
Reinstall it from your DVD. If you don't have a DVD then download the trial version from www.mactopia.com and use your license key from your current copy.
Don't use WiFi for Migration Assistant. Use an Ethernet connection if cannot connect them using either Firewire or Thunderbolt.
If one of the computers is not working, then don't expect Migration Assistant to work.
Currently Being ModeratedFeb 6, 2013 6:56 AM (in response to Amorific)
you will need to use carbon copy software whic you can get it from google which copy what every data is there in you old hardisk it copys to new hardisk
Currently Being ModeratedFeb 6, 2013 7:11 AM (in response to Apple-USA)
Never clone from one computer to another unless they are exactly the same model and never ever clone from an older to a newer computer.
Kappy's answer is correct. I will add however that since Apple has removed FireWire from its Mac line that I strongly recommend that users migrate from one Mac to another by using a TimeMachine (or clone) backup. WiFi is much too slow and while ethernet theoretically is fast I've experienced enough issues (stalls and slowdowns) that I don't recommend it.