Disabling the Ctrl-Alt-Del Key Combination

If not in a domain on the computer type MMC, File, Add Remove Snap-in, Group Policy Object Editor, Local Computer, Finish, OK, expand Local Computer Policy, computer configuration, Windows settings, Security settings, Local policies, security options, scroll down until you see Interactive logon: Do not require CTRL+ALT+DEL

If in a domain you can create a GP from the server.

Note: If this policy is disabled, any user is required to press CTRL+ALT+DEL before logging on to Windows (unless they are using a smart card for Windows logon).

Thanks for the tip but I want to how to disable the functionality of the ctrl-alt-del key entirely.

Thank you.

Maybe you should word it better and sorry for not understanding, when you say disable and lockdown the function in GP is enable or disable, so lockdown sounds like you want it there so you can use it and you ask to "disable" it, which is the feature I explained. If you want it to not be there then enable it.

If this policy is enabled on a computer, a user is not required to press CTRL+ALT+DEL to log on. Not having to press CTRL+ALT+DEL leaves users susceptible to attacks that attempt to intercept the users' passwords. Requiring CTRL+ALT+DEL before users log on ensures that users are communicating by means of a trusted path when entering their passwords.

If this policy is disabled, any user is required to press CTRL+ALT+DEL before logging on to Windows (unless they are using a smart card for Windows logon).

By default it's "Not Defined"

Another miscom my apologies what I mean by "disable" is so when I press the ctrl-alt-delete combination on the Windows 7 nothing happens rather than the standard screen giving my options to Lock the computer etc.

Thank you.

You can not disable its functionality. (physically on the keyboard remove the del key)
As works2011 commented, you can disable/disallow certain optoins for the users to do, the one you are asking is not one of them.

Cheers for the advice.