http://support.microsoft.com/kb/154780
As long as the page has no outside hyperlinks and you have no other apps running to Alt+tab to AND assuming the user is unaware of Keyboard Shortcuts for Kiosk Mode you should be good to go.
The following script on your webpage would help with preventing Keyboard Shortcuts:
document.onkeydown=DisableCtrlKey;
function DisableCtrlKey(e) {
var keycode;
if (window.event) {
keycode=window.event.keyCode;
}
else if (e) {
keycode=e.which;
}
if(keycode == 17) {
void(0);
}
}

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