Install

I know you already are familiar with this function from my previous post.
This is the function to render main window where headerLabelTxt and headerProgPercent.
def renderMainWindow():
    # Create Main window
    mainWindow = Tk()

     # display the menu
    mainWindow.configure(menu=menuBar)

    # create App Menu
    # need to update this control key for Windows
    mainMenu = Menu(menuBar, tearoff=0, name='windows') # name creates system app menu
    mainMenu.add_command(label="About " + appName, command=renderAboutDialog)
    mainMenu.add_separator()
    mainMenu.add_command(label="Quit " + appName, command=lambda: on_cancel_button('quit'), accelerator="Ctrl+Q")
    mainMenu.bind_all("<Control-q>", on_cancel_button)
    menuBar.add_cascade(label=appName, menu=mainMenu)

    # Create Menu Bar
    menuBar = Menu(mainWindow)

    # Create Top Frame
    topFrame = Frame(mainWindow)
    topFrame.pack(side=TOP, fill=X)

    # Add Header to Top Frame
    headerLabelTxt = StringVar()
    headerLabel = Label(topFrame, textvariable=headerLabelTxt, justify=CENTER, anchor=CENTER)
    headerLabelTxt.set('Select the software you would like to install')
    headerLabel.pack(pady=pixelRetinaMod(10))

    headerProgPercent = IntVar()
    headerProgress = Progressbar(topFrame, length=pixelRetinaMod(560), orient=HORIZONTAL, mode='determinate')
    headerProgress['variable'] = headerProgPercent
    headerProgress.pack()

    headerProgLabelTxt = StringVar()
    headerProgressLabel = Label(topFrame, textvariable=headerProgLabelTxt, foreground='#777777', justify=CENTER)
    headerProgLabelTxt.set('Click Install to Start')
    headerProgressLabel.pack(pady=(0, pixelRetinaMod(10)))

    .......

    # Here, I follow your approach.
    mainWindow.bind('<<InstallCompleteHeaderProgressBar>>', on_install_complete_header_progress_bar) # for header progress bar
    mainWindow.bind('<<InstallCompleteHeaderProgressText>>', on_install_complete_header_progress_text) # for header progress text
    mainWindow.bind('<<InstallComplete>>', on_install_complete) # this worked in updating the cancel and install button

Here are the virtual events that I removed from function on_install_button_active which involve Tkinter widgets.
And I followed your approach.

# This worked
def on_install_complete(event):
    cancelButton.destroy()
    installButton.configure(state=NORMAL)

# This did not worked
def on_install_complete_header_progress_bar(event):
    headerProgPercent.set(100)

# This did not worked
def on_install_complete_header_progress_text(event):
    headerProgLabelTxt.set('')
    headerLabelTxt.set('Installation Complete')


And this is the function on_install_button_active, whole code
def on_install_button_active(button, model, selectcount):
    # Main install Section
    global pulseTimer
    global installStatus
    global itemIconImage
    global view
    global headerProgress

    # set busy flag
    installStatus = 'busy'

    # Count items
    itemCount = len(titleList)

    # Disable Checkboxes and header Checkbox
    for listItem in range(itemCount):
        itemCheckBox[listItem].configure(state=DISABLED)
    headerCheckAll.configure(state=DISABLED)

    # START installing apps one by one

    # using itemSelectCount to do progress increments
    progInc = float(100 / selectcount)
    itemIncCount = 0

    headerProgPercent.set(0)

    for listItem in range(itemCount):
        # Check which items are selected True in list column 0
        itemSelected = checkItem[listItem].get()
        if itemSelected == 1 and installStateList[listItem] != 'removed':
            # set currentHeaderProgress for each process at start
            currentHeaderProgress = headerProgPercent.get()

            # With selected items ...
            headerLabelTxt.set('Installing Software ' + str(itemIncCount + 1) + ' of ' + str(selectcount))

            # Start Install software
            installError = ''

            if updateList[listItem]:
                updateText = 'Updating'
            else:
                updateText = 'Installing'

            headerProgLabelTxt.set(updateText + " " + titleList[listItem])

            # Set Focus on item
            itemCheckBox[listItem].focus_set()
            itemCheckBox[listItem].focus()


            outFileName = urlList[listItem].split('\\')[-1]  # IP_ConfigServerMT64_8130027b1_ENU_windows.zip
            outFileExt = fileExtension(outFileName)  # .zip
            outFile = os.path.join(appsFolder, titleList[listItem])

            # Extract, for zip files
            if outFileName:
                if outFileExt.lower() == 'zip':
                    try:
                        headerProgLabelTxt.set("Extracting " + titleList[listItem] + " ...")
                        extract_files(outFileName, outFile, listItem, progInc)
                    except:
                        installError = "[Error] Could not extract %s" % outFileName


                    # If installation folder exists
                    if os.path.exists(outFile):
                        headerProgLabelTxt.set(updateText + " " + titleList[listItem] + " ...")
                        # Applications Install folder path
                        appFilePath = os.path.join(outFile, 'ip')
                        # Change directory to execute setup.exe
                        os.chdir(appFilePath)
                        try:
                            get_exitcode_stdout_stderr_zip_dvd(titleList[listItem])
                        except:
                            installError = '[Error] Installation of %s not successful.' %titleList[listItem]
                else:
                    # for DVD
                    headerProgLabelTxt.set(updateText + " " + titleList[listItem] + " ...")
                    appDVDPath = urlList[listItem]
                    # Change directory to execute setup.exe
                    os.chdir(appDVDPath)
                    get_exitcode_stdout_stderr_zip_dvd(titleList[listItem])
            else:
                installError = "[Error] No ZIP/DVD file for " + titleList[listItem]


            itemProgressPercent[listItem].set(90)
            headerProgPercent.set(setHeaderProgress(listItem, progInc, currentHeaderProgress))

            # Check if component if indeed installed
            appInstallPath = os.path.join(installationDir, descriptionList[listItem], appFileList[listItem])
            if os.path.exists(appInstallPath) and not installError:
            else:
                installError = "[Error] Could not install %s" % titleList[listItem]

            # END of main item Install

            # De-select checkbox, I am now here
            checkItem[listItem].set(0)

            # Check if install ok and set icon and progress bar
            if installError == '':
                installStateList[listItem] = 'installed'
                itemProgressPercent[listItem].set(100)
                headerProgPercent.set(setHeaderProgress(listItem, progInc, currentHeaderProgress))
            else:
                installStateList[listItem] = 'error'
                itemProgressPercent[listItem].set(100)
                headerProgPercent.set(setHeaderProgress(listItem, progInc, currentHeaderProgress))
                # Set to 0 after main progress update
                itemProgressPercent[listItem].set(0)

            # If selected Inc for each item as we know not how many here
            # Move progress incrementally depending on number of install items
            itemIncCount = itemIncCount + 1
            displayInc = progInc * itemIncCount

            # Update main progress bar at the end of each item install
            headerProgPercent.set(displayInc)

    # These are the calls that involved Tkinter widget which I removed
    # Software Install Done - The End -
    # headerProgPercent.set(100)  # not working?!
    # headerProgLabelTxt.set('')  # not working?!

    # Followed your approach to call virtual events, Have tried when parameter to head and mark but did not work and GUI hangs/freeze
    mainWindow.event_generate('<<InstallCompleteHeaderProgressBar>>', when='tail')

    # One of the call that involved Tkinter widget which I removed
    # headerLabelTxt.set('Installation Complete')  # not working?!)

    # Followed your approach to call virtual events, Have tried when parameter to head and mark but did not work and GUI hangs/freeze
    mainWindow.event_generate('<<InstallCompleteHeaderProgressText>>', when='tail')

    # Reset install status
    installStatus = 'complete'

    # This is the only call to virtual events that worked
    mainWindow.event_generate('<<InstallComplete>>', when='tail')

    refreshGui(mainWindow)