Secure desktop is the desktop for things like UAC screens, and the Windows logon screen.

This uses a completely different NVDA profile, with a separate speech/braille config. By default it's set to espeak.

My first guess is your machine is going to sleep, and it's asking for your password when it wakes up. You can turn off sleep in the power options.

If you want to copy the current configuration to the secure desktop, so it uses the same speech/braille settings as the logged in NVDA, you can do that.
* Press ctrl+NVDA+G, to open the NVDA General settings.
* Press the button that says Use currently saved settings on the logon and other secure screens (requires administrator privileges).
* If the secure desktop appears during this process, it's probably an UAC prompt. Press alt y.
If you want NVDA to work at the logon screen, the General settings dialog has a checkbox for that as well.

On 6/27/2016 9:54 PM, John J. Boyer wrote:

If I don't do anything on my machine for a while it goes to Secure
Desktop, whatever that is, and NVDA is not working. The only way I can
get out of it is to shut down the machine and turn it back on. Does
anyone know what Secure Desktop is and how to get rid of it?

Thanks,
John