Restoring a hack job hack

I bought a newish Wii (black) from some friends who've since moved on to PS3. Homebrew is installed and the system is at 4.2, but I am aware that they used it for "things not to be discussed" and that the info they used to install HBC came from lots of sources, which I suspect means it was downgraded (I think the black originally came installed with 4.3u?) and maybe had others mods that aren't supported here.

I really only want to use HBC for emulators, but I want to get my Wii as much on the up and up as I can. My question is...can I wipe however they did this downgrade/install and use a fresh install of Homebrew? (If yes, which basic guide do I follow?) Also, if I do this and upgrade to the latest HBC, is it then safe to upgrade to 4.3u?

Hopefully asking about this isn't breaking the rules, I'm almost wishing I'd saved the money for a new console instead of having to deal with the constant bricking fear since I don't know what they did to it.

Thank you!

You should certainly upgrade to the latest version of th Homebrew Channel. After running the HackMii installer, please post your log file here so we can see if anything needs to be fixed for stable operation. Do this weather the installer runs correctly or not.

Also, please tell us what sytem menu your Wii is running on. I think the first black Wii's may have had 4.2 on them.

I will get to work on this hopefully later on tonight and post results then, thank you!