Keyboard unresponsive only at Win7Pro login

I've got an HP Pavilion dv3000 laptop with Windows 7 Professional SP1 installed, and it is on the company's domain. To get to the login screen, I need to type control-alt-delete, but the keyboard doesn't respond there. My current work-around is to use the mouse to show the onscreen keyboard, then click ctrl, alt and then delete keys on the onscreen keyboard. Once I do that, the login screen appears and the keyboard becomes responsive and remains so throughout the windows session. After the computer sleeps or is logged out, it reverts to the unresponsive keyboard situation.

How do I get the keyboard permanently enabled?

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