Windows Explorer won't load and keep freezing

I've been having problems with Windows Explorer not loading properly for a few weeks now. It does various things, the first one is not loading at all. The files won't load, and the green loading bar just never finishes, not matter how long I leave it. The magnifying glass just keeps circling, and the cursor just stays as that blue circle (I've added an example below).

Sometimes it will load to some degree; the files will sort of load, but the thumbnails will remain entirely white (some still won't show up at all), the folders empty, and often when they're like that and I try to right click on a white thumbnail the page will freeze up completely, and I won't even be able to close it. I have to restart my computer. This is happening constantly now. Sometimes it will happen as soon as I log on, other times it will be alright for an hour or so, and then start this.

Unfortunately my computer has no suitable restore points on it to try and restore it back to how it was before all this started, and I have no idea what caused it. I've had Windows 7 almost since it was first released, and the same computer, and I've never had this problem before. I'd be very grateful for any other suggestions on how to fix this. Thanks.

Making the assumption you can't reach desktop, you'll have to do the scans "offline".

With the help of a friends pc, download and burn to cd the Kaspersky and BitDefender offline rescue disc isos.

Then, with your internet connected so they can update, boot up with each and run full scans.
Tell us if they find and fix things.

Next step would be to boot up with a W7 disc and go to "repair" and get to a command prompt and run chkdsk /f.