I can't change sharing after a restore

I found this little snippet and don't know whether it's relevant to your problem, but I'll post it all the same:

"I thought I was having the same problem as other users here, but it seems the actual problem is simply terrible interface design. I now realise that the 'Share with' menu always shows a lock against the option 'Nobody', making it appear that the files are not shared even when they are.

Surely a tick should appear on this menu against the selected option, and the lock symbol should disappear when the files are no longer locked? If you look at the bottom of the screen, you can see that there is a message "State: Shared" once the files are shared, but this does not show the full state - that is, whether they are read only or read/write."

Thanks for that, it seems to clear up part of the issue. I am stil struggling here, I've just noticed that I cannot make a pic my wallpaper, on that I get the message

''This image cannot be set as wallpaper. An internal error occurred''

The image is a pic I took last week, and up til now I was able to do as I wanted with it. Now it is slightly greyed out in my pic folder and I can not edit or anything.

I checked the properties and the file hidden box was checked, I unchecked it and things were just the same.

How weird is this?

What file format are your pictures in?

What program do you use to open your pictures?

Clutching at straws now: go to Windows Explorer>Organize>Folder & Search Options>View>Files & Folders>Always Show Icons, Never Thumbnails>Apply>OK.

If that doesn't work you can just go back and click Restore Defaults.

It seems the only thing you can do now undo your system restore to try and put things back to where you started.