Your post is a little confusing.  Does Michael (which version?) already reside on your hard drive?  IIRC, there is no separate DAZ installer for M4, so you can add Michael's runtime folder to Poser as an external runtime.

Which Poser version are you using?  It sounds unusual to be denied installation unless you are using the PoserPro series.  Regular Poser versions contain a Poser.exe in their folders which DAZ content exploit when looking for an installation folder.  The Pro series contain PoserPro.exe which is not recognizable by DAZ installers.  There are workarounds, but we need to know which version you are currently using.