Ever wondered what that little button in the lower left-hand corner of the Windows Vista logon screen is?
Download and unzip the software, and then right-hit the setup file and choose Run as Administrator.
Choosing to run it as administrator is such an important step that the software will remind you regardless.
If you wanted to re-enable it, just launch the setup again and nudge the Enable button.
And now you’ll get this message anytime you press the Ease of Access button.
Download Ease of Access Disabler from softpedia.com