Hi, on the first point, to open a PDF, Firefox will always download it ''somewhere'' -- either in the web content cache (the URL in the address bar starts with http or https), or your "Save files to:" folder, or the Windows Temp folder (a hidden option). I'll give more details on how to manage this below the line. On the second point, download history normally is managed together with browsing history. Is Firefox losing your browsing history as well, or just the download history? One difference with download history is that it doesn't seem to last as long -- mine only goes back to October 12th. If you need a long-term reference to downloads and download locations, you may need to find an add-on for that. ---- '''Managing PDF Download Locations''' The first lever is the setting you use on the Settings page, Applications list. If you choose: "Open in Firefox" - many PDFs will be stored in the web content cache along with web pages, and some will be stored in ordinary disk folders (when the server sends the Content-Disposition: attachment header). You can (A) override "attachment" disposition to save more PDFs in the cache and/or (B) switch Firefox from saving PDFs from your "Save files to" folder to the Windows Temp folder. Details below. "Use [relevant application" - all PDFs will be stored in ordinary disk folders. You can switch Firefox from saving PDFs from your "Save files to" folder to the Windows Temp folder. Details below. "Always ask" - if you choose an "Open" option in the download dialog, the PDF will be stored in an ordinary disk folder. You can switch Firefox from saving PDFs from your "Save files to" folder to the Windows Temp folder. Details below. '''Settings Changes''' '''''(1) Just for PDFs, override "attachment" disposition to "inline"''''' When your handling action is "Open in Firefox", all PDFs can now be opened as web content and saved in the cache instead of a regular folder. Here's how you set this up: (a) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future. I'm using this so I feel comfortable mentioning it.'' (b) In the search box in the page, type or paste '''browser.download.open_pdf_attachments_inline''' and pause while the list is filtered -- requires Firefox 103 or later (c) Double-click the preference to switch the value from false to true '''''(2) For all the downloads Firefox saves to disk and opens automatically, change from the "Save files to" folder to the Windows Temp folder''''' (if you made the change in #1, this will affect other kinds of files rather than PDFs) Here's how you access it: (a) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' (b) In the search box in the page, type or paste '''browser.download.start_downloads_in_tmp_dir''' and pause while the list is filtered -- requires Firefox 102 or later (c) Double-click the preference to switch the value from false to true This would not affect files opened with inline disposition; those will still be in the web content cache.