How to access the Registry

Of course you did.

This seems to be a problem where after returning to Windows 7 the parts of the registry containing the information for Scheduled Tasks is restored, but the task definitions themselves are not restored (still Windows 10 definitions) resulting in an inconsistency between the two and then things don't "line up", you are going to get these kinds of errors.

You might be able to fix it using a link from CodePlex but who knows what other things are not going to be the same or what other problems you are going to discover - you may end up having to whack your system and reinstall your Windows 7 from scratch.

Here is a link to a piece of software that will attempt to repair this condition with Scheduled Tasks.

https://repairtasks.codeplex.com/

You should first read the Home tab to better understand the problem.

On the Download tab you can download the RepairTasks.zip and the Windows7Tasks.zip and unzip them to your desktop or someplace you can find them.

It wouldn't hurt to at least browse some of the Reviews from other people with similar issues.

The go to the Documentation tab and at least read through the process so you can sort of understand what your are going to be doing.

Then you can launch and run the RepairTasks.exe and let it scan your system for problems.

If there are no problems you are done.

If there are problems you can go through the documentation and follow the directions to attempt to repair your tasks or even replace all of the default Windows 7 tasks with copies of "good" tasks from a fresh Windows 7 installation (the contents of the Windows7Tasks ZIP file has all the tasks).

If you have problems with Repair Tasks, go to the Discussions tab, register and start a discussion out there.

I have simulated many error conditions with Windows 7 tasks and this Repair Tasks fixes everything I could break on purpose but I have never done the Windows 10 back to Windows 7 thing and don't plan on it.

If you look in this Windows 7 community there are many many posts of problems with that upgrade/downgrade procedure...  booting problems, task problems, authentication problems, update problems,  lots of things have the potential to become afflicted but by some miracle the upgrade and downgrade actually works sometimes.

If you are able to get your Scheduled Tasks patched up who knows what other issues you are going to come across later of things that used to work and now don't.

When the process fails it looks like you are going to be in for potentially days and maybe weeks of "trying" things and suggestions that often don't work and the best thing to do probably is to backup all your personal data (possible even if your system does not boot) and just reinstalling your Windows from scratch or performing a factory reset on your system of unspecified make and model.

You've already started down the path of "trying" things and that isn't working out so well is it?  It might have gone better if somebody would have asked what the error message was and if the system used to work properly what do you think happened to it

• but now we know.

Reinstalling is a lot of work but may be the only way to be sure you can get back to stability.

Yes, I did!  In fact, I'm afraid I made a very silly mistake. I did the upgrade without doing a new backup of my HD. After the upgrade failed, I chose the option to return to the previous build. All the earlier restore points had been wiped out and the Backup facility wasn't working any more.

Well - at least we know what the error message is sort of ( I was wondering why nobody asked for that).

Prior to this incident did you upgrade to Windows 10 and downgrade or make an effort to go back to Windows 7?

Thank you both, but I'm afraid that neither solution worked. The Registry now looks exactly like it's supposed to in the superuser file but clicking on Backup and Restore in the Control Panel still produces no effect. (I have rebooted the computer in case something had to be read into memory.)

By the way, there was an Automatic Scheduled Backup key above the SystemImageBackup but when I closed the regedit and opened the task scheduler, I got a ton of messages about various items being corrupt or has been tampered with. I did remove the Automatic Scheduled Backup key (after rebooting with it still there) but the Backup facility is still not operative.

This page has full (manual)  instructions with screenshots on how to do reset the backup and restore configuration.

Resetting Windows 7's backup parameters - Super User : http://superuser.com/questions/410329/resetting-windows-7s-backup-parameters

The .reg file method also does the same.