Windows 7 64 bit Home Premium Thumbnails will not appear

A month ago Windows forced an Update. At the end of it it asked me to run a disk error check - the one with the black box. At the end of this it showed a Codec error which no one including my professional IT support people have been able to fix. When I rebooted all my jpg thumbnail previews had disappeared and were substituted by standard Microsoft icons. I have read and tested every fix I have seen on the web and none work. My IT support people have had the computer for hours and run Tweaking.com and have not fixed it. We have run three different anti virus tools plus Eset and they find nothing. In addition the Windows 10 update will not download and fails and Skype will not update. As I use images for my business and cannot identify them except by file name this is a disaster. My IT support suggest a new computer but it is running fine. this appears to be a software issue

Matthiesen, regarding your picture thumbnails, have you been able to open the pictures? If you can open the pictures the first thing I would look into is the file associations. What type file and what program opens the file is what the system might require to generaye a thumb rather than an icon.
Let me know what you find.

The files are associated with Photoshop but even if you change to Photoviewer it makes no difference

[FIX] Windows Explorer Doesn?t Show Thumbnail Previews in Windows Vista and Later - AskVG

Yes I am afraid we tried that first. No joy
nor this
Fix image previews and thumbnails in explorer on Windows 7? - Super User

Hi Cyclops
after the Codec error report not only will WIN 10 not download and install as I hoped it might cure things, but as I said Skype will not update and remove the old edition and of course the thumbnails do not preview. Now I find that I cannot do a screen print either because when I do a blank square appears without the image with the message 'the image cannot be displayed' Other than these things the 64bit computer runs normally!

Don't even be playing around with Windows 10 while you have not resolved your original problems? Why don't you just do a system restore back to before the bad windows update took place and start all over from there.

My IT people tried all the tricks they knew and gave up on me. I feel sure they have tried this one but I will enquire. It will mean the loss of a lot of data since then I suppose.