I have a similar problem. I am running Windows 7 and had some videos on my HX90V camera. I could see the files, but when I tried to transfer them from camera to PC using a USB cable I kept getting a message a message saying "Resource in use". My PC doesn't have an SD card read, so I put the SD card in my wife's laptop which is running Windows 10 (which I think is rubbish). I could play the video files on the laptop with no problems. I then got a USB memory stick so I could transfer the files to it and hopefully from the stick to my PC. However, when I plugged the SD card into my wife's laptop a few day later after doing nothing but taking a few still photos the video files had vanished according to Windows 10, and I can no longer see them on my PC via the camera and USB cable.However they are still on the camera as I can play them on the camera. Not only that, the folder system on the SD card has been completely screwed up. The files were originally in a folder called DCIM, with sub-folders, one for each day when photos or videos were taken. Now the still photo files are all in a single sub-folder called MSDCF, and no trace of the video files.
I'm completely baffled.
