Well I have been given this problem to work out. My parents being computer technitions come across plenty of strange problems. but this one has stumped me and my parents.
So this is what happins. (Its not my wii and I havent seen it personaly)
Turn it on. play games its fine. Go on the internet and it comes up with a rouge antivirus trogan. This makes the internet unusable on the wii and the wii needs to be restarted. It is also comin for the wii to not turn on anyway.