you really needed to start a new thread to ask this question??? ...you could have asked it just as easily asked in the other thread you just started (they are related)....
so you updated....assuming you had bootmii/boot2, assume it is now gone (if the drive light gives you two quick fashes when you turn the wii on, then you still have it)
...if it is gone, you can reinstall it though....just run the hackmii installer from HBC and reinstall it just as you did before... SD:/apps/folder/boot.elf (for hackmii installer)
i think Modmii actually has the hackmii installer as an app in HBC (for reinstall in the event you had to install it on an IOS other than 58 to begin the mod)
piece. of. cake.