Sio serial module install problem with ActiveState

[Conrad]

Greetings,

I have a need to print from Win98SE to a little 
serial label printer provided by United Parcel, so 
based on Mark Hammond's recommendation in 
'Programming on Win32' I decided to try the Sio 
module at http://starship.python.net/crew/roger/

My problem:

The Sio installer dies looking for:
HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\2.2\InstallPath

I am using ActiveStates Python 2.2.2 build 224 on Win98SE.

ActiveState apparently does do registry setup, for example,
the HKEY_USERS\.DEFAULT\SOFTWARE tree contains the
\Python\PythonCore\2.2\InstallPath keys. I re-installed
Python, thinking I had blown the registry, but the keys
that Sio wants are never set.

FWIW, PyPGSQL, wxPython, and the egenix MxBase packages all 
find Python on machines with ActiveState and install OK. 
I don't know what they are checking on install.

Can anyone suggest a fix/workaround for someone who is just 
a bit befuddled by registries, or did I perhaps grab the 
wrong Sio? ( I got SioModule22.EXE at 171184 bytes from:
http://starship.python.net/crew/roger/ )

BTW, this serial printer is apparently pretty much a 'dump
and go' type device - the only thing the printer seems to
be capable of returning is a 4-byte error code after a special
error report command is sent to the printer - other than that,
all of the data and commands seem to move downstream only,
with no return from the printer expected. Is Sio overkill for
this, i.e. is there some incredibly simple "open a serial port
under Win32 for write only" command I'm missing in the basic
Python stuff?

Many thanks,

Conrad