plpgenbtldr creates only a small kick starter program that you are able to run the boot manager or the installer from the windows boot menu. it does nothing more or less. its no installer or anything special. its only a small program that creates a small kickstarter file. this file has to be added to the windows boot menu.
so is the plop boot manager installed to the mbr or is it started by the windows boot menu? the only way to install the boot manager to the mbr is to use the boot manager installer. the installer must be started by the floppy, cd, network, windows boot menu or any other way, but IT MUST BE STARTED. there is no other way (except some special ways when you know what you are doing) to install the boot manager to the mbr.
did you install to the mbr or not?
if not, search in this forum how to use bcdedit to remove the boot manager entry or look at the microsoft manual of bcdedit.