The patch kit was installed with NHD-7.
Beginning with the release of Patch Kit 3, patch kits were
incorporated into the NHD-7 kits. As a result, when you
installed NHD-7, you automatically installed the current
patch kit. These patch kits cannot be removed. However,
you can remove any subsequent patch kits. For example,
if you installed NHD-7 with Patch Kit 4 and later installed
Patch Kit 5, you cannot remove Patch Kit 4, but can
remove Patch Kit 5.