need help with video driver on natty

[glenn opdycke-hansen]

I had upgraded from 10.10 to 11.04 on a desktop that was running
ubuntu with a nvidia graphics card.
The upgrade completed but the hardware driver showed that the current
nvidia driver was "activated but was not currently in use."
I had removed this, rebooted, and now the login screen will not
appear.  (oops)  Now is see that activated but not in use is typical.

Is there a way from the command line to re-install the NVIDIA
accelerated graphics driver?

Thanks in advance.

--glenn