I'm not sure if it is a nvidia driver or DirectX issue, but half life 2 engine used to hang on my box just as raymond suffered.  I didn't know it could be this simple, just a shortcut hotkey.

It's lucky that halflife2 does not block hotkeys but some games do.  ctrl+alt+del hotkey is unblockable so i wrote a small program to make use of it. CtrlAltDelAction(src) is a program i wrote to execute specified exe when you click ctrl+alt+del.

Example

(To Install)
C:\> CtrlAltDelAction.exe taskkill /F /IM hl2.exe
(or drag some .bat file like killcss.bat over CtrlAltDelAction.exe)

(To Remove)
C:\> CtrlAltDelAction.exe
(or just double click the CtrlAltDelAction.exe)

usage: hit ctrl+alt+del after install and "taskkill /F /IM hl2.exe" will be executed right before taskmgr.exe is executed