Maybe you should connect it to the Internet first,and then you should update your WiiU.

What exactly is the error code and the accompanying error message?

This is either because you have a weak connection or because Nintendo's servers are currently overloaded.  The latter case is more likely given other people's issues right now, so try again in a few hours.

try sending them a email using http://www.nintendo.com/consumer/webform/

I kept getting error code 108-0075. I just kept redoing the update and eventually it got through. I had to do it 7 or 8 times, though.

I managed to get part way through an update download before my connection died (my home cable is terrible).  After resetting my cable modem I couldn't reconnect and download the update - I would get any number of 105 and 108 error codes consistently.  Sometimes the failure would be immediate, other times it would take up to a minute. 

Turns out the problem was with my wifi connection.  Despite it being set to auto-select an IP and auto-configure DNS settings it was failing to do so.  In fact, it was attempting to use an IP that was already in use by another device.  Any number of re-attempts would provoke this response - it would never select a new IP.  What I did was hard-wire the IP and DNS settings and try again.  Lo and behold, it is once again downloading (albeit slooooowly).

You might want to ensure that your wireless is REALLY working via a connection test.  The device gives no other indication of reason outside of that screen.  Why it returns multiple diffierent potential failure codes during update makes no sense at all when the reason is so consistent and simple.

Hope that helps!

I as well are having a similar problem. On the other hand I have perfect Internet connection but it refuses to update. Tried several time. Nintendos wii u server seems to be working fine like it said on the web site.

If anyone could help that would be great!