All Wii hackers need a Wad installer and there is no better than Waninkokos Wad Manager.
Wads are a bit like zip files, they usually contain channels that when installed with Wad manager show up on your system menu, they are also used for installing/uninstalling new system files to your wiis NAND chip including IOS/cIOS and system menus.
A bad wad can semi-brick your Wii (banner brick from incorrectly sized banner) so always be careful of where you get your wads from, it is important to have some sort of brick protection if you are installing a lot of wads to your system, a NAND backup with Bootmii is the best solution but Preloader can help uninstall bad wads too, so if you have either or both of these you don't really have to worry about the dreaded 'banner brick'!
Using Wad manager is simple, copy the Wad manager folder into the 'apps' directory on your SD card and make a folder called 'wad' on the root of your card to put your wads in.
When run it will ask for an IOS to use, it should default to IOS249 if you have it and this will allow it to work fully, if you don't have IOS249 then any IOS with the fake sign bug should work. If you get a 2011 error then the IOS you have selected does not have the right permissions to work, see about getting IOS249 on your system by using this guide.
From Wad Manager 1.5 the ability to install wads to an emulated nand has been added, to do this you need a full nand dump on a separate device. Yet again it has been modded by wiininja and sorg and is available for HBC or as a channel.
There are several versions of wad manager listed here for download, try 1.7 first and if you have problems, go back a version ie 1.5. until you get one that does what you want it to.
Download wad-manager-1.4.enh.mod_by_Sorg
Wad Manager 1.5 Mod3 HBC Version
Wad Manager 1.5 Mod3 Channel Version
Wad Manager 1.5 GUI
Wad Manager 1.7 mod HBC and Channel versions
Wad Manager 1.7
If there is any information you think i should add to this then please pm me and lmk :)
