Windows 7 users might have noticed the Ease of Access button on the bottom left corner of the logon screen. This button allows you to use the Ease of Access features such as the narrator, magnifier, high contrast, on-screen keyboard, sticky keys and filer keys right from the logon screen.
But the fact is that only few people access the Ease of Access Center from here. Also some other users might use your computer and they could make some changes to your windows when you are not around. Here is a small tool called the Ease Of Access Disabler which lets you enable and disable the Windows Logon Ease of Access Center button.
When you this button, windows launches the Ease of Access center.
So here is an application/tool that allows you to enable and disable Ease of Access button as per your convenience.