It has happened two times this week and I'm getting scared. I called nintendo and they told me they'll charge me money since my console is two years old. They also told me to format my Wii memory.

Did you format your Wii memory after the first time?

...how did you corrupt them?

no because I'm not sure if it'll work

I got that message once a few months ago...simply resetting fixed it and I never got the message again.

unknown. I didn't MOD my wii or hack it. All I do is download from VC and wiiware, go on the internet, play games and update my wii.

Well I got two. One on sunday when I was about to play RE:4 Wii. the second was when I was about to play Star Rouge Squadron III for GCN.

If you don't try what the experts suggest, I don't know what to say.  Backing up all your saves to sd and doing that is what I would of recommended if Nintendo hadn't recommended it first.  (Besides for the easy test of pulling the power plug for a minute first).  You should be able to redownload all your wiiware and vc games at no charge.

I had my geometry wars save file get corrupted, but other than that no problems so far. Is it just those games save files that are corrupted? Obviously I have nothing to add as I can't really help you, but I'm just interested.

you download from wiiware, this is the problem, you have downloaded something , but your wii messed up and didn't fully install it, so bits and parts are missing, I have the same problem. Currently the only two solutions are to get a new wii, or send in it for repair, repairing it might prevent you from losing all your stuff on the wii, but getting a new one, unless you use a sd card and transfer everything over before the sign comes up saying corrupt files, will make you lose everything. Sometimes its not even downloading something from wi-fi its just using wi-fi thats messing up your wii, or you have one of the older versions that have something wrong with them when they use wi-fi.As well as this, it may just be the fact that your wii has run its lifetime and is just messing up and destroying itself.I am about to take mine in for repair, if it doesn't work, well i'll say hello to the new wii.Idk about formatting the memory, but I doubt you'll be able to fix it formatting the memory by yourself, you'll have to be able to locate the corrupted file(s) and delete them yourself.If my solution was a bit to late oh well, at least it will help people for future use :)