Did you only recently purchase your Wii or did you upgrade? If you upgraded did you upgrade safely using Waninkoko's method, or did you download an official Nintendo Update? Downgrading is a very risky thing to do, I did it myself, but my Wii was neither a LU64+ model and was downgraded from 3.4E to 3.2E.
When you say "wad installer file" do you mean Waninkoko's "Wad Manager"? My guess would be that you are missing an IOS or cIOS, have you tried reinstalling them? (such as cIOS38rev15 etc?)
If so, please read Dogeggs' wonderful guide here.