John,
.
I'm running the latest version, Z3INS15.COM, which doesn't require pointing
to the SYS.ENV file.  For the earlier versions, you would type:
	A0>Z3INS SYS.ENV PATH.COM
or if the files were not on the default drive/user:
	B2>A15:Z3INS A0:SYS.ENV A0:PATH.COM
.
When I first started up my system, I did not understand about Z3INS.COM.
I did finally figure out that the programs needed to know the address of
the Environment package, so DDT peeking revealed the location of the
address at 0109h (low byte) and 010Ah (high byte).  I just substituted the
address into those locations with DDT and everything worked just fine.	Z3INS
does exactly the same thing, but makes it much quicker and easier.  If, for
instance, you should modify your system such that the Z3 addresses moved, you
can create a file named UTILITY.INS containing all of the Z-System utilites
on your disk using an editor with one file name to the line.  Then running
	A0>Z3INS SYS.ENV UTILITY.INS
would install all of the files at once with the new address.
.
The file should then look something like this for SYS.ENV at FB4Eh:
BEFORE:
-D100
0100 C3 0B 01 5A 33 45 4E 56 01 00 F3 2A 09 01 CD 29 ...Z3ENV...*...)
0110 05 21 00 00 39 22 14 04 21 81 00 22 0E 04 CD DA .!..9"..!.."....
.
AFTER:
-D100
0100 C3 0B 01 5A 33 45 4E 56 01 4E FB 2A 09 01 CD 29 ...Z3ENV...*...)
0110 05 21 00 00 39 22 14 04 21 81 00 22 0E 04 CD DA .!..9"..!.."....
.
Hope this clears it up a bit.  Sorry about forgetting about the earlier 
version syntax.  Something I'm not sure about is installing Z3INS.COM?
It, too, has the environment address at 0109h.	I poked that in with DDT,
but maybe it can install itself if pointed to the SYS.ENV file.
  Later, -- kent address at 0109h.	I poked that in with DDT,
but