Hello Anthony,
Thank you for posting your query on Microsoft Community.
With the issue description, I understand that experiencing issue with Windows Update after upgrade to Windows 10 and also not able to run any command in command prompt. I will certainly help you in getting this issue resolved.
This issue might be occurring because of any third party software conflict. To diagnose the issue, let's check running this command in safe mode.
Try to boot the computer in Safe Mode. Safe mode is a diagnostic mode for Windows that starts your computer in a limited state. Only the basic files and drivers necessary to run Windows are started. This helps us in identifying
whether the issue is due to some third party programs conflict. The word Safe mode appear in the concern of your monitor to identify which windows mode you are using. You can follow the below Microsoft article
Note: Please refer to the section: To get to Windows Startup Settings in the Windows Recovery Environment
http://windows.microsoft.com/en-in/windows-8/windows-startup-settings-safe-mode
If you're able to run the above command in safe mode, restart the computer in normal mode and run SFC scan.
Hope this information is helpful. Please write back to us if you need any further assistance, we'll be glad to assist you.
Regards