PDFs have opened on my laptop perfectly forever, apart from today!! I get the following error. I have rebooted, and re-installed Reader several times, but it still won't open a document. How do I fix it??

Did you uninstall the original reader before re-installing. Just a thought.

19 minutes ago, jsk said:

Did you uninstall the original reader before re-installing. Just a thought.

Sensible suggestion, sadly I uninstalled, reinstalled, and fault persists...

After re- install, all looks well... but it isn't!

Hi Stephen, I also had problems with Adobe Reader recently. I suspected that an update had basically destroyed it's compatibility with Windows 7. Fortunately I happened to have a copy of a much older version - Adobe Reader 10 - so uninstalled the newer one and installed that instead. All good now. I don't know if you can find it online now but worth a try if you can.

More and more stuff is becoming unusable on Windows 7 so as far as possible I make sure nothing updates silently in the background.

Just now, mjt said:

7 minutes ago, mjt said:

i Stephen, I also had problems with Adobe Reader recently. I suspected that an update had basically destroyed it's compatibility with Windows 7. Fortunately I happened to have a copy of a much older version - Adobe Reader 10 - so uninstalled the newer one and installed that instead. All good now. I don't know if you can find it online now but worth a try if you can.

More and more stuff is becoming unusable on Windows 7 so as far as possible I make sure nothing updates silently in the background.

Sir, you are a friggin' genius!! Just did that and have got my ability to open PDFs back! I seem to have lost the ability to 'print' a word document in PDF but I can cope with that. Thank you. Not everyone needs the latest bells & whistles bit of software, I'm content to use old stuff...

downloaded older version from here...

Just discovered a free virtual PDF printer here, works perfectly.

Glad to be of service 😀

I have been using this PDF printer for a number of years. It installs as an additional Windows printer. Another free PDF utility I've found useful is Sejda PDF desktop which does all kinds of conversions and can edit PDFs.

The file referenced in the error message is a "library" (contains code used by a program, essentially, which you can tell from the fact that the file extension is '.dll'). From the name of it I assume it's a "system library" (part of Windows), though one should never assume such things, since sometimes malware authors disguise the names of things to trick you into assuming that they are benign.

If it's a legit system file and is missing, it could be because it was removed by a Windows update, which would only happen either by mistake or because it's become obsolete. If it's by mistake then you'd have to wait for Microsoft to correct the mistake in a further future update. If obsolete then you'd have to wait for an updated copy of the PDF reader that works with newer libraries. Usually third party software have plenty of forewarning before a system component that they rely on gets removed though, and they'd have issued an update that relies on other updated components well in advance of its removal, so if this is the latest version of the PDF reader, that's strange. Of course Windows 7 has also not been receiving updates for a few years now, so it would seem strange for an update to have now gotten installed and removed this component, unless it was a rare emergency patch. Another hypothetical possibility could be malware messing with your system, though why it would remove this library is odd. I suppose another possibility is that the PDF reader no longer supports Windows 7 and has received an update, and the new version can't load now due to needing a system library that only exists on newer versions of Windows.

Ah, doing a quick search for the DLL file brought up a discussion which indicates that an update to the PDF reader is responsible. Something is mistakenly broken with the update, and they're investigating and a potential fix is on the way with a further update. Things like this happen to many software projects from time to time, so don't be too harsh towards them.

Jumping back to an older version, as you have is the only solution to viewing PDFs with that software for now until the mistake is fixed.

Note that Firefox and Chromium have built-in PDF support, so as long as your browser settings are correct (set to view PDFs in the browser rather than just download them), you could open and view PDFs directly in your browser (open a new tab, press CTRL+O, and navigate to the file) as an alternative.

13 hours ago, rd457 said:

Ah, doing a quick search for the DLL file brought up a discussion which indicates that an update to the PDF reader is responsible. Something is mistakenly broken with the update, and they're investigating and a potential fix is on the way with a further update. Things like this happen to many software projects from time to time, so don't be too harsh towards them.

13 hours ago, rd457 said:

CAN'T DELETE!!!

13 hours ago, rd457 said:

CAN'T DELETE!!

Odd that I never contemplated a 'fault' with Adobe update, though after your observation, on a google, yes, they appeared to have royally screwed up. Pleasing to note so many very useful workarounds. Including a 15 year old version (Adobe Reader 10)

Still compared to some horrendous experiences I had once with Windows 8, where an update once stopped it connecting to the internet, this one was easy...

On 2/20/2026 at 11:44 PM, rd457 said:

another possibility is that the PDF reader no longer supports Windows 7 and has received an update, and the new version can't load now due to needing a system library that only exists on newer versions of Windows.

That was my suspicion since Windows 7 updates ceased years ago. I doubt there will be any fixes forthcoming as I imagine Adobe are not concerned about backward compatibility. I actually prefer the presentation of Reader 10 compared with the new versions anyway.

Personally if an application does what I want of it I see no need for constant updates unless they are actually bugfixes. That's why I've stuck with Windows 7. I like the GUI better than W10 and as Stephen has pointed out we know our way round it so why swell Micro$oft's coffers with unnecessary upgrades?