How do I fix a “(filename) Class not registered” error on Windows 7 64-bit (Windows Explorer, details below)

Question

Ever since September 29th, I have been unable to save files from the internet directly to windows explorer. For example, if I try to save a picture, it will bring me to the "choose where you want to save" but all Libraries (documents, pictures, videos) are empty. When I attempt to save the file, I get the error "(filename) class not registered. I can, however, bring these folders up directly from Windows Explorer by clicking on on my desktop. I've tried so many things, from system restore (which won't work because if I try to restore before the 29th, I get an error saying a particular file could not be restored), to cleaning my registries using various programs (CCleaner and Glary utilities). I have scanned my entire computer with Avast! and Malwarebytes, and I have scanned the Windows Explorer file specifically, nothing strange was found. I can also download things that don't require me to pick a folder, such as videos that download directly to "My Downloads". This is quite the inconvenience, as, for example, I can't even upload pictures to Facebook or other sites from my Library, but the fact that it happened out of nowhere troubles me even more. I've noticed many other people have this error, and I've found no solution to my particular problem. I'd very much like a swift answer to this question, thanks in advance!