For the "call phone" feature I have this message above its on screen keyboard:
"Please download the voice plugin to make a call".

I follow the the link to do so and use the download link found there for downloading the file "GoogleVoiceAndVideoSetup.exe". Attempts to install this file fail. The error message is:
"GoogleVoiceAndVideoSetup installation error 0x80040707"

There is another message box that appears briefly with the message:
"Installation failed. Another installation of a Google applications is already in progress."

But there is no other installation in progress. Searching the web I find the suggestion to disable the "Google Update Service." This service appears twice in Windows XP's Services manager. There it shows two instances of this are invoked. One of the instances is with the the command "GoogleUpdate.exe /svc" and the other with the command "GoogleUpdate.exe /medsvc". Their startup types are "Manual" and the former instance has a status of "Started" at boot up. The later is not invoked at boot up. When I attempt to install after disabling both service invocations and reboot I get the error:
Google Update Installer failed with error 0xa0430606

This is a different error and I do not know if this difference represents a step forward or backward.

Running registry cleanup programs did not help. I have reached the end of my wits on this and need help with it.