Win XP - Strange problem

I have a strange problem.
When I press "Ctrl + Alt + Delete" to bring up Windows Security dialog box, nothing happens. I have re-started the computer several times with no results. I need some help on this one. I have no idea where to start looking for the problem.

 

Oromocto--Can you access Task Manager by right clicking on a blank spot on the TaskBar (near the clock) and clicking Task Manager? If yes, perhaps one of those keyboard keys is not working.
But if you cannot access Task Manager that way either, look here
http://www.kellys-korner-xp.com/xp_t.htm
and scroll down to Task Manager.
Note there is the possibility of a virus. So if the other fixes do not help, you may want to follow the procedures here
http://www.windowsbbs.com/showthread.php?t=37074
P.S. If the TaskBar procedure works, and C+A+D still does not, you may want to look at the Kellys-Korner reference anyway.

 

Thanks Welshjim for your very comprehensive answer. I have checked out some of the suggestions. It looks like I will have to mess with the registry.

 

Welshjim:
I ran a search for taskmgr.exe and it was located in two places. C:\I386 and C:\Windows\Service Pack Files\i386. I double clicked on it and it came up fine, so I dragged a copy of the shortcut to the desktop and it brings up the task manager just fine. I tried using the other set of keys but they didn't work. I know I should fix the registry using kelly's-korner but am a mite too timid. Do you think that I will be OK the way it is? It does work!

 

There should be a copy of taskmgr.exe in your windows\system32 folder. If it's not there, that's your problem. Check that folder for the file. If it's not there, copy the one on your desktop to that folder and see if it works.

Note. It may be winnt\system32. It should be in a system32 folder that is a sub folder of the folder you have windows installed to.

 

Zander and Welshjim:
Yes, that did it. I guess I can now simply delete the one on my desktop?
Thanks a bunch for your help. I printed out the contents of the links Welshjim sent---Should be useful some day. Thanks again.

 

Glad to hear it's fixed. And, yes, you can delete the one on your desktop.

 

Ctrl +Shift + Esc should also do it.