Haven’t knew or observed GoogleToolbarUser_32.exe process running under processes list in Task Manager this process is called as Google Toolbar Broker. This process belongs to Google Toolbar for Internet Explorer. So whenever you’re running IE with Google Toolbar (recently it has Google Instant search added) installed, you can see this process in TM.
Where GoogleToolbarUser_32.exe is located?
GoogleToolbarUser_32.exe runs from “C:\Program Files\Google\Google Toolbar”. This is not a virus. There is no official explanation from Google what this process do?
How to disable this process?
You can’t disable this process, if you kill this process it will start running again when you log off /restart your Computer.
This process disappears only when you uninstall Google Toolbar for Internet Explorer from your Computer.