That's hard to say based on your description. By the way, you may consider posting your question in the appropriate forum category so that you can get the best responses and so that people interested in these types of topics can learn from the discussion.
So based on the error you described it seems like your IP was unable to be be successfully leased from the DHCP service.
Were there any other devices on your network affected?
If other devices are being affected with the same probelm, chances are it's a new router you need (I'd recommend a cisco or netgear)
If it's just your laptop, you might want to get a USB wifi adapter as it could be the integrated WLAN card that's nackered.