I had successfully connected the Wii to my Buffallo router and I was doing the system update and the first one went through ok. Then, the wii restarted and it was doing another system update, when all of a sudden it froze at like 20%. I went to check what was going on and found out that I lost my cable signal. I then restarted the cable modem and it booted fine , but the update wouldn't go past that 20%, so I shut off the power (even though it says do not power off) and restarted it and it asked me to do the update again and this time, it went through till it was successful. I know this might seem like a silly question , but could I have damaged the wii somehow when I shut it off while it was still trying to do the update (I was searching for the wii for 2 weeks until I found one ; hate to think that I might have damaged it this early ) or would the second time I updated it just rewrite over any corrupted file??
If it updated, everything should be fine. But if you experience any problems then just call Nintendo and they will send you a replacement console free of charge as long as you send in your defective console within the time limit they provide. =)