What is the exact text of the message? A screen shot would be best.
I can't read Korean, so unless you translate the text in that dialog, I can't provide any help.
It's asking me if I want to opne this file. On the line below the name, it's indicating that it's created by an unkown publisher/sources. On the bottom box, the option states that "always ask before opening this file." On the very bottom, it says "this type of file can cause harm to your content. If the content of the file is suspicious and untrusted, do not open this software." Yes, it says "software" when it is not really.
What happens if you begin by launching Acrobat and open the file by selecting: File > Open
It's not clear to me what software is causing that message to be displayed, but it doesn't look like it's Acrobat.
It opens fine. This type of message "used to" only pops up when I try to open a setup file (.exe). I have no idea what is going on.
It doesn't look that you are using Adobe Reader, are you? And what .exe file has to do with PDF? You need to make sure that a) you are opening PDF files (.pdf) with Adobe Reader and not some .exe file.
It is also suspect which downloading software you used to download your PDFs from the Web site. Which setup file you're trying to open? For which application? Why is your post on this forum?
Hello CannotBeOpened and George Johnson, please excuse my lateness in joining this debate, but this week I have this problem for the first time. After a Windows update, I now find I cannot open PDFs that were emailed to me without first unchecking a pop-up box on each one separately. Even after saving them to my own hard disk and placing them into various destination folders, the pop-up box appears every time until I uncheck that box.
This problem only applies to PDFs and not to other types of file, so issues that I initially suspected concerning zone information settings are not the cause. And I am definitely using the latest Adobe version (10.1.10) to view the files.
Here is a screen shot of what I see, which may be similar to the one that CannotBeOpened showed except this is in English:
Notice the nature of the message that must be unchecked. It says Always ask before opening this file which is different from the message that I usually see when opening suspicious file types, which says Always ask before opening this type of file. Here is an example of that one, it is part of the normal security one would expect for potentially malicious attachments, and perfectly welcome:
Now one might suspect that it is the origin of the PDF that is the cause. For example, the PDFs that were emailed to me when I noticed the problem were made by an accounting software program and may have been secured in some way. But I made the file "RandomPDF" here myself on my own computer using Irfan View and emailed it to myself, and still this problem persists.
These messages are designed to protect you from bad files coming from the internet. If it has recently started for PDFs, it is because the bad guys have found a way to make PDFs a threat. One arriving in email has come from the internet, even if you sent it out there in the first place.
It is a standard Windows feature. You can turn it off, apparently, though I wouldn't. See disable "Open File Security Warning"
Hello Test Screen Name, thanks for your quick reply. You got that piece of advice from a 5-year old forum post. I tried it and it worked, of course. But I wouldn't dream of leaving a hole that big in my security!
There are other workarounds on the forums. Sadly, these all seem to require access to the group policy editor, which I cannot use because my machine is still on Vista Home Premium.
This issue is clearly outside the scope of what Adobe can do. It's a Windows Update issue, they have done something in the registry, so I have posted a similar request for help on the Microsoft forum. If I get an answer there I will post a link here.
I have debated this matter with one of the MVPs on the Microsoft forum, here. It seems that the Windows Update itself is not the problem, the issue is the version of Adobe Reader that I have installed on my machine.
I had Reader 10.1.10 installed. The MVP, (PA Bear, who is extremely helpful, he insisted upon first making me sort out Java, antivirus and other issues on my machine) suggested that I upgrade to Reader 11.0.7. But the download page for this version redirects to a page with 10.1.4 on it, an earlier version than the one I had already. I uninstalled 10.1.10 completely, acquired 11.0.7 from FileHippo, against the advice of PA Bear, although this was evidently quite safe (and even came without the McAfee drive-by) and installed it.
Now the problem is resolved. I can happily open the PDFs emailed to me without the warning box. And I have checked the security settings of the Internet Zone to make sure the "Prompt" option is still enabled for "Launching applications and unsafe files" and it is so.
The question remaining is why Adobe Reader version XI, released October 2012, is both not offered as an update to me and not available from the Adobe web site. Here are the OS requirements, copied from the page
Tech specs | Adobe Reader XI on the Adobe web site:
Microsoft® Windows® XP with Service Pack 3 for 32 bit or Service Pack 2 for 64 bit; Windows Server® 2003 R2 (32 bit and 64 bit); Windows Server 2008 or 2008 R2 (32 bit and 64 bit); Windows 7 (32 bit and 64 bit); Windows 8 or 8.1 (32 bit and 64 bit)
Notice my OS Vista Home Premium SP2 is not listed here. Is there any reason for my exclusion from this?
Vista was specifically excluded when version 11 was developed, so it is not officially supported on Vista. At the time, the number of Vista installations was very small compared to XP and Windows 7, and was released about the same time that Windows 8 was. People have reported that it works on Vista, but you won't get any help from Adobe with it.