Preventing malicious users from tampering with the Windows operating system on your kiosk necessitates that system keystrokes like Ctrl-Alt-Del be blocked. This can be surprisingly difficult since Windows doesn’t give you a built in method for doing this. The next logical step would be to have your kiosk application filter out these keystrokes which turns out to be a problem since your kiosk application is running in user move not kernel mode (see user mode vs. kernel mode explanation).
This leaves you with three options:
- Create a kernel mode upper filter driver that listens for system keystrokes and discards them before they reach the operating system.
- Use a 3rd party kiosk lockdown software that filters keystrokes for you.
- Replace the physical keyboard with a touchscreen keyboard that does not include any modifier keys (i.e. Ctrl, Alt, Shift, Windows Key, etc…)