See this support article about Applications > Content Type and changing the Action. https://support.mozilla.org/en-US/kb/applications-panel-set-how-firefox-handles-files

This did not work. Like I said it converts Adobe PDF, Microsoft Word and Excel to Lumin. I changed to Adobe PDF in Firefox instead of default and no change. My phone number is Ted

edit phone# from public and search/spam bots as nobody here does direct support by phone or email.

Are you going to get back to me?????

Ted

Apart from being an app for Google Chrome: Lumin is a PDF viewer that doesn't come pre-installed;   it's installed manually or by other apps you install on your computer.
Have you checked to see if it's in the 3-bar menu > Add-ons > Extensions   ?
Or in Windows Control Panel > Programs   ?

It isn't anywhere. I double checked the applications and on the right of PDF it says Acrobat Reader is the default. Nowhere is there a Lumin Viewer installed but that is what all files sent to me are shown in with no way out! I never installed it manually.

Ted

'Been searching and finally found this  :
www.ghacks.net/2014/04/22/disable-internal-pdf-reader-firefox-chrome/
Any good   ?

No that didn't work either. I can't work with my computer doing this. Every attachment that comes in shows up in Lumin and I can't do anything with it. BTW I am using XP.

Ted

teddietz said

No that didn't work either. I can't work with my computer doing this. Every attachment that comes in shows up in Lumin and I can't do anything with it. BTW I am using XP.

You said earlier   'all files sent to me',   and here you're saying   'every attachment that comes in'   ...... And you can't do anything with it   .......
You haven't installed   Lumin;   it's nowhere to be found on your computer, and you can't do anything with incoming files . Makes me think that you can't do anything with incoming files because they use Lumin and you don't   ........
I've run out of ideas;   (so sorry   ....... )
I sure hope somebody else will come to your rescue &nbsp !

I asked and they are not using lumin. Very weird. It affects word, excel and adobe.

Ted

teddietz said

I asked and they are not using lumin. Very weird. It affects word, excel and adobe.

Just got a brainwave:   Word and Excel are Microsoft programs   (and you'll probably find Adobe Flash Player in Windows Control Panel);   post a question on the Microsoft support forum   (it's similar to this forum and for
Windows XP users as well) :
answers.microsoft.com/en-US/windows/forum/windows_10

Getting really bizarre now. Microsoft won't recognize the scrambled letter in the robo protection code I retyped. I did this about 5 times!! Won't let me start an account to ask questions.

Ted

This is beginning to sound like a SciFi story;   I've called for help   ......

Do you use Gmail or another site that usually gives you a choice about how to open message attachments (e.g., download vs. open in Drive)?

Is it a personal account, or a business account that could have managed settings?

I use Gmail

Could you check whether Lumin PDF is installed in your Google Drive and possibly set as default. This thread has the steps (I haven't gone looking myself since I don't have this):

How to remove Lumin PDF as default PDF viewer? - Google Product Forums

Google Drive? I have have an inactivated Google Chrome on my desktop. All three defaults for PDF are Adobe Reader.

Ted

This is Google Drive: https://drive.google.com/

Okay thanks but now it comes up in Google Sheets. I am going to delete everything that says Google and see if that helps.

Also I can only uncheck the rest of the items. Lumin is gone but now files come up as Goggle Sheets with no selection for word or excel. I'll try a pdf

Adobe PDF's are now Adobe PDF's but excel sheets are Google Sheets even though I unchecked Goggle Sheets, Google Docs, etc. and clicked Done. Now what?

Ted