Will the RubyInstaller’s Tcl/Tk conflict with an existing Tcl/Tk?
No. The (optional) Tcl/Tk support is private to the RubyInstaller and will not conflict with an existing Tcl/Tk installation you may already have installed. If the RubyInstaller’s private copy does conflict, we’ve overlooked something and it’s a bug that must be fixed. Please let us know ASAP if this ever happens.