bootmii file will not load after wii upgrade

hi, i have upgraded my wii to allow new games to be played as it was on a very old version but in doing so the bootmii will not start.
i have checked the folder and "armboot.bin" and "ppcboot.elf are within the bootmii.
my wii is working fine but i cant get access to the homebrew channel as it wont boot up. i have done something incorrectly but i have no idea what!

can anyone suggest anything please

thanks

your description is pretty vague. you didnt mention what you upgraded from and what you upgraded to. and you dont mention which version of bootmii and the homebrew channel you had.
if you have upgraded to 4.2 or 4.3, it would have removed all the version of the homebrew channel before 1.0.7. if you had boot2 v2 or v3, then the upgrade would have removed bootmii from there as well.

just grab the latest hackmii installer and run it and install the stuff from it that you want to install.