Here is a code snippet that I wrote recently for IronPython, correcting some registry information that I put by mistake in our image that is used for cloning client PC’s. I’m sure PowerShell script would be even shorter and cleaner, but I had to come with some working code in a hurry.

# -*- coding: cp1250 -*-
# odbc_patch.py -- patching my shallowness
# AlesK.

__about__= "IronPython script // odbc_patch2.py by AlesK"

from Microsoft.Win32 import Registry

# -----------------------------------------------
# How to enumerate a node from ODBC.INI.
# Print System DSN names with SERVER key value if present
# (SERVER key is mandatory for MS ODBC for Oracle, MySQL ODBC,
# etc., but not for Oracle supplied driver!
# 
# For complete reference to Regirstry class refer to:
# msdn.microsoft.com/en-us/library/microsoft.win32.registry.aspx
# You can use:
# Registry.ClassesRoot|CurrentConfig|CurrentUser|
#          LocalMachine|PerformanceData|Users
# ------------------------------------------------
system_dsn = Registry.LocalMachine.OpenSubKey('Software\\ODBC\\ODBC.INI')

for dsn in system_dsn.GetSubKeyNames():
    dsn_key = system_dsn.OpenSubKey(dsn)
    server = dsn_key.GetValue('SERVER')
    # print only those DSN's that were created with MS ODBC)
    # and thus have SERVER defined
    if server is not None:
        print("DSN=" + dsn + " SERVER=" + str(server))

# ------------------------------------------------------
# How to read and change value in registry.
# Registry.GetValue
# Registry.SetValue
#
# The plot: by mistake I added MS at the end of SERVER variable
# for DSN's that are using MS ODBC driver. Instead of
# SERVER = ORAXMS I really want SERVER = ORAX, striping off MS.
# Candidates in my case are: ORAXMS, ORAYMS, ORAZMS.
# ------------------------------------------------------

odbc_dsn = ['ORAXMS','ORAYMS','ORAZMS']
odbc_node = "HKEY_LOCAL_MACHINE\\Software\\ODBC\\ODBC.INI"
odbc_key  = "SERVER"

for dsn in odbc_dsn:
    value = ''
    value = Registry.GetValue(odbc_node + '\\' + dsn, odbc_key, value)
    if value in odbc_dsn:
        Registry.SetValue(odbc_node + '\\' + dsn, odbc_key, dsn.strip('MS'))
        print("ODBC.INI: patched " + dsn + " SERVER=" + dsn +
              " to SERVER=" + dsn.strip('MS'))
    else:
        print("ODBC.INI: " + dsn + " - nothing to patch.")

Sample output:

C:\Scripts\IronPython\Registry>ipy odbc_patch2.py
DSN=ORAXMS SERVER=ORAXMS
DSN=ORAYMS SERVER=ORAYMS
DSN=ORAZMS SERVER=ORAZMS
DSN=ORA6MS SERVER=ORAT
ODBC.INI: patched ORAXMS SERVER=ORAXMS to SERVER=ORAX
ODBC.INI: patched ORAYMS SERVER=ORAYMS to SERVER=ORAY
ODBC.INI: patched ORAZMS SERVER=ORAZMS to SERVER=ORAZ