Hi Aachel,
It seems to be an issue with the Graphics Card on the computer, I would suggest you to please update the Graphic Card drivers on the computer.
And then reimport the images in Lightroom.
Regards,
Tanuj
Faststone and the Windows viewer are displaying the embedded JPEG preview. What you are seeing is an indication that you have a hardware problem somewhere in your system. It could be a failing hard drive, a failing camera card, a bad USB cable if you are using one. It's a problem that you are going to have to isolate.