I am switching computers so I transfer some pdf files from the first computer(Win 8) into a memory stick. Then I transfer from the memory stick to the second computer( Win 7). But all the pdf files become Firefox HTML Documents. 1) When I copy from the first computer, I open the memory stick to verify the copy is pdf file on the first computer. But, when I plug the memory stick into the second computer, I open the memory stick and it shows they all are Firefox HTML Doc files. 2) I tried with another memory stick and did the same thing. The strange thing is the same pdf file in the memory stick is shown as pdf file when on the first computer, but shown as HTML file on the second computer. The files were in form of pdf files originally from the SECOND computer. I transfer to the FIRST computer, then transfer back. That's when all the trouble started. I attached one file that show as HTML file, but as you can see, it even show up as pdf file. It is inconvenient to open as HTML as it keep opening the internet. Does anyone know how to fix this. Thanks ps: Reason I transfer to the first computer (Win 8) was because it's a newer computer, but it constantly crashes ( maybe is Win 8). I just want to go back to the older computer that is more stable.