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Why can I no longer download and read .pdf files

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I have never had any problems downloading and reading .pdf files until I 'upgraded' the Adobe reader to version 11. Now all attempted downloads fail because "I don't have the necessary helper application or even C:\DOCUME~1\Will-o\LOCALS~1\Temp\Back Channel II - The Vietnam Betrayal - Chaps 1&2.pdf could not be opened, because the associated helper application does not exist. Change the association in your preferences. What in the world is going on and how do I fix it?

Under 'Tools - Applications - Adobe Acrobat Document, the I've selected 'Use Adobe Reader.' However since I also have Adobe Acrobat 8.3, I've tried substituting that for the Reader, but that doesn't work either. Please help.

I have never had any problems downloading and reading .pdf files until I 'upgraded' the Adobe reader to version 11. Now all attempted downloads fail because "I don't have the necessary helper application or even C:\DOCUME~1\Will-o\LOCALS~1\Temp\Back Channel II - The Vietnam Betrayal - Chaps 1&2.pdf could not be opened, because the associated helper application does not exist. Change the association in your preferences. What in the world is going on and how do I fix it? Under 'Tools - Applications - Adobe Acrobat Document, the I've selected 'Use Adobe Reader.' However since I also have Adobe Acrobat 8.3, I've tried substituting that for the Reader, but that doesn't work either. Please help.

Chosen solution

You might try the following:

(1) Change your preference to "Preview in Firefox" and use the download button to save the file. But that is an extra step.

(2) Change your preference to "Always ask" and see whether you can get the file to open that way.

(3) Clear your application preferences file (it sometimes becomes corrupted) and start again. Note: these are only the preferences for which applications handle which types of content, not all of your Firefox preferences.

To do that:

(i) Open your current Firefox settings (AKA Firefox profile) folder using

Help > Troubleshooting Information > "Show Folder" button

(ii) Switch back to Firefox and Exit. Your Windows Explorer window should return to the foreground. Pause while Firefox finishes its cleanup.

(iii) Rename mimeTypes.rdf to something like mimeTypes.old

(iv) Restart Firefox. It's likely you will be defaulted to "Preview in Firefox" and hopefully the paths for Adobe Reader and Adobe Acrobat will now be correct if you choose one of those.

Any luck?

Read this answer in context 👍 7

All Replies (2)

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Chosen Solution

You might try the following:

(1) Change your preference to "Preview in Firefox" and use the download button to save the file. But that is an extra step.

(2) Change your preference to "Always ask" and see whether you can get the file to open that way.

(3) Clear your application preferences file (it sometimes becomes corrupted) and start again. Note: these are only the preferences for which applications handle which types of content, not all of your Firefox preferences.

To do that:

(i) Open your current Firefox settings (AKA Firefox profile) folder using

Help > Troubleshooting Information > "Show Folder" button

(ii) Switch back to Firefox and Exit. Your Windows Explorer window should return to the foreground. Pause while Firefox finishes its cleanup.

(iii) Rename mimeTypes.rdf to something like mimeTypes.old

(iv) Restart Firefox. It's likely you will be defaulted to "Preview in Firefox" and hopefully the paths for Adobe Reader and Adobe Acrobat will now be correct if you choose one of those.

Any luck?

Modified by jscher2000 - Support Volunteer

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Brilliant! Problem solved! Thanks so much.