WinXP rsync local copy to USB drive

[Charles Gregory]

I've encountered an error while trying to "find" my way to
my goal. But first, let me state my goal in case there is a
pre-canned solution that does what I want (which would avoid
the effort of figuring out the error...):

I want to invoke the rsync *client* (but NOT the server) to
make a local copy from one windows drive to another. Ie.
rysnc -ax /cygdrive/c/path/sourcedir /cygdrive/e/mirrorofsourcedir

I want to do this *without* "installing" a Windows package,
and without "registering a Windows service".

Ideally, I want to put the rsync.exe and cygwin.dll on the
USB drive, so that I can give this to a completely tech
illeterate friend and say, "Plug this thumb drive in and
it will automatically make a backup for you."

I am currently trying the DeltaCopy package of rsync.
BUT I am NOT using their install or wrapper. I downloaded the 
"raw" binary distribution, which, according to their docs, simply 
requires a copy-n-paste of the files anywhere on the C: drive.
I did this and added the directory to Windows environment PATH.

So in *theory* I should be able to directly call the rsync
executable with the following command line, but when I do
I get THIS error:

C:\>C:\DCRsync\rsync.exe -ax "/cygdrive/c" "/cygdrive/d"
rsync: pipe: Operation not permitted (1)
rsync error: error in IPC code (code 14) at 
/home/lapo/packaging/rsync-3.0.4-1/src/rsync-3.0.4/pipe.c(121) [sender=3.0.4]

I googled for references to this error and came up with a report on this 
forum, of this same problem occuring on "cwRsync". So I suspect the 
problem is not dependent on the wrapper package. I can't try cwRsync 
without installing their server. Something I would rather not do if I have 
no intention of using it (plus which it takes away from the original goal 
of having this run straight from a thumb drive with no install).
Would their rsync binary be any different than DeltaCopy's version? 

So, is this messing up because "Cygwin" needs to be "installed"?
If I believe the DeltaCopy docs, it should be enough to have the
cygwin binary in the same directory as rsync.exe?

And yes, I'm running as an "administrator" account on Windows. :)

Just in case someone is thinking of pointing me at another (non rsync) 
Windows backup solution, I'm not totally against the idea, but please 
don't be suggesting packages that require windows installation or which 
use a different backup strategy like incremental files. I don't care if 
it has a different name, but it really needs to work like rsync from a 
command line.

Thanks!