Press and release on a Windows Vista touch-enabled monitor may leave a ring on display
When using Windows Vista with a touch-enabled display, the default “press and hold” behavior is to perform the equivalent of a mouse right-click. This may be configured through the Pen and Touch control panel.
Ordinarily, when you press a finger to the touch screen and hold, an animated ring starts to appear to indicate that you are entering the “press and hold” mode. If you wait for the ring to complete drawing and then remove your finger, the ring should disappear and the context menu should be displayed.
In rare instances, if you quickly move your finger while removing it from the screen, the context menu will not be displayed, and instead the “press and hold” ring will stay on the screen and finger touch may no longer function correctly.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2021067.