Revert Permissions to all folders quickly?

Windows 10 seems to have changed the permissions settings to all my files and folders - and I have lot of them (documents, photos, music etc).

I must have at least 30 000 images stored as I'm a pro photographer and thousands of documents. I currently can't save or change anything as I'm told the files are read-only and I don't permission to do that. This is seriously delaying my work.

I'm not on a network and I am the administrator.

Can someone advise me if...

A) There is a universal way to do this throughout my drives (C and D) quickly or if I have to do it by folder (which could take forever).

B) The easiest way to do it.

C) Microsoft are aware of how they have seriously messed up our computers and if they are doing anything about it.

Thanks for any help with this.

Thanks for the reply, but that didn't work for me . I also tried changing the security settings under the main documents folder. I got an error message saying access was denied.