Hi Myra Hale Walters,
Thank you for reaching Microsoft Community. I'm sorry to hear that you're having trouble accessing your Surface Pro. I understand how frustrating this is especially that the device needed for an online course.
It sounds like your device may have switched from using a password to a PIN for login. Does it give you also an error message like "PIN is unavailable"? If possible, please provide us with the error.
Also, what were the last things that you did on the device the last time that you were still able to access it? Were there changes made on it?
To troubleshoot, kindly try first doing a Force Shutdown on the device to clear the hardware cache by pressing and holding down the Power button for 30 seconds.
If the issue persists, kindly try these steps below to uninstall updates through the Windows Recovery Environment (WinRe) before we conclude with a Reset:
Boot first the device to WinRe by doing these:
On the log in screen, press and hold the Shift key
Tap the Power icon on the screen then select Restart
Release the Shift key once you see the Choose an option screen
On the Choose an option screen, select Troubleshoot
Select Advanced options
Select Uninstall Updates
Choose first Uninstall Latest Feature Updates then follow the instructions
After that, restart the device and see if you are now able to log in
If not, follow the steps again and this time, select the Uninstall Latest Quality Update option
Once you are able to log in on the device, please make sure to reinstall updates properly:
Go to Windows Settings > Updates & Security
Select Check for updates and make sure all updates installed including Optional updates
Let me know how it goes.
Kind regards,
Marrion