"Show Windows in Taskbar" option from the ToolsOptionsView broke
 

I like to have each workbook have its own tab in the taskbar. This function
used to work by selecting the above referenced option, but no longer.
Checking and unchecking the option has no effect. I've also uninstalled and
reinstalled Excel to no avail. I really REALLY don't have the time to
reinstall right now.

Does anyone have any idea how to fix this annoying defect?