If you wish to use the RubyInstaller installation package, you need to choose the "without Devkit" version: - Run the installer and it *should* do everything for you. You'll still need to install MSYS2, but will not have to add the ruby executable path to your system PATH var. - ...
Though normally weI do not enthuse about "bleaching" mold (since leaving a dead mold spore in place can still be harmful and can leave toxins), careful cleaning of otherwise already HEPA-vacuumed debris-free surfaces with a proper bleach solution (5%) is an effective end measure for hard su...