I could lock my Windows XP workstation using CTRL+ALT+DEL, K. That keystroke combination does not work on Windows 7. Is there a method of locking Windows 7 using just keystrokes?
Use Windows+L. If you use AutoHotKey you can reprogram Windows+L to do other things too, like lock your session, and also wait 10 seconds and put monitors to sleep. Powerful little hotkey program.