PDF file type not recognized

Ok, so you actually have exactly two files. Once, one of these files shows up as PDF file and is working correctly, the other time this file(?) shows up as a CHK file and is broken.

• I first thought this might then be an issue with file extensions not being displayed in the WIndows 10 system. That way, a file named File1.chk.pdf might appear to be named File1.chk. However, it would then still be a PDF file...
• On the PC, where it appears to be a CHK file, can you open other PDF files?
• Are you using exactly the same disc in both computers (the same USB flash drive, the same DVD/CD whatever)? Or have the files been copied and you are in fact using two different versions (so that something strange may have happened during copying)?
• When you rightclick on the CHK file and go to properties, what does it tell you as "File type" and "Open with"?

Finally, please open the CHK file with a text editor, e.g. with Notepad and paste us the first 10-15 signs, which you see there into your response. It will not contain actual file content, but it should contain a magic number, which tells us, what the heck this CHK file contains...

All PDF files attached to emails open fine. Using same flash drive both machines. It gives me the choice now of Nuance PDF Viewer, Adobe reader (both fail now) & notepad reader= "
‡² p€IÑÏ
E : \ S o u t h A s i a \ 2 0 1 4 _ 0 9 _ 1 5 _ 1 1 _ 1 2 _ 5 9 . p d f"

walkerpbus said:

‡² p€IÑÏE : \ S o u t h A s i a \ 2 0 1 4 _ 0 9 _ 1 5 _ 1 1 _ 1 2 _ 5 9 . p d f

In order to be a PDF file, the content must start with "%PDF". If what you posted above are the first signs inside of the CHK file, then I can definitely tell you one thing: This is not a valid PDF file.

I think I now understand the situation you have, but I cannot tell you, how this should be able to happen.

If you take one pair of files, compare the file size of the PDF file and the size of the according CHK file. I am pretty sure that one of the following two things is the case:
a) Both are identical. In this case, the PDF file will not be working (as it contains something like the stuff you posted above) or
b) Both are different (because you are looking in the wrong folder or whatever). In this case, the question is, why the PDF files are not visible when the flash drive is put into Windows 10.

If your files are not absolutely top secret, maybe you can upload one pair of these files: The PDF file as you see it on the Windows 7 PC and the CHK file as you see it on Windows 10. I would then have a look into them and see, what they actually contain.
That is the last offer I can give.

Joergi said:

In order to be a PDF file, the content must start with "%PDF". If what you posted above are the first signs inside of the CHK file, then I can definitely tell you one thing: This is not a valid PDF file.

I think I now understand the situation you have, but I cannot tell you, how this should be able to happen.

If you take one pair of files, compare the file size of the PDF file and the size of the according CHK file. I am pretty sure that one of the following two things is the case:
a) Both are identical. In this case, the PDF file will not be working (as it contains something like the stuff you posted above) or
b) Both are different (because you are looking in the wrong folder or whatever). In this case, the question is, why the PDF files are not visible when the flash drive is put into Windows 10.

If your files are not absolutely top secret, maybe you can upload one pair of these files: The PDF file as you see it on the Windows 7 PC and the CHK file as you see it on Windows 10. I would then have a look into them and see, what they actually contain.
That is the last offer I can give.

How do I upload? I looked at the characters above, & none stands for file or upload, etc.