Sticky Keys
The sticky keys are an accessibility feature provided by Windows.
The functionality of the Sticky Keys allows for people who have difficulty pressing multiple keys (eg CTRL + ALT + DEL), to use the SHIFT, CTRL and ALT with a single press on these buttons.
Sticky Keys can be activated by pressing 5 times on the SHIFT key.
It is also possible to disable this feature by going to
Control Panel/Accessibility Options/keyboard tab
Then in Sticky Keys section, click Settings and then check or uncheck.
Under Vista:
It is also possible to enable or disable this feature by going to
Control panel / Ease of Access Center / Make the keyboard easier to use
Under
Make it easier to type check or uncheck to Enable or disable the Sticky Keys ant click on
Apply to validate the changes.