Which version of priiloader do you have? It's possible that all you need to do is just put the hacks.ini (or hacks_hash.ini) in the root of the SD card again. Most likely, you just have the internet & disc updates block hack enabled (that or your internet is incorrectly configured).
Just so you know: neither formatting the wii nor updating by internet will properly eliminate all traces of hacking. And I don't see why you're reformatting things to add new stuff. Not only is it useless at best, it's also dangerous if you remove the wrong stuff. If you want to rehack, treating it as a virgin wii is usually (or even always) the best option.
EDIT: and oh: to create a new topic, there's a button just above the stickies on the right side of the screen called "start new topic".
EDIT 2: hmm...it's also on the bottom right, just below all the threads. Was it really that hard to find?