We're hearing from many users: Outlook always prompts for permission to open attachments and the checkbox for "Always ask before opening this type of file" is grayed out. This is due to User Access Control (UAC) restrictions in Windows.
There are two ways you can address this:
1: Run Outlook as Administrator and open the attachments, removing the check from "Always ask before opening this type of file" box. After you set the desired file types to open without asking, you can run Outlook normally.
2: If you know the file types and are comfortable editing the registry or want to change it via policy, you'll need to identify the file type in HKEY_CLASSES_ROOT or (buried under) HKEY_LOCAL_MACHINE if Windows 10 64bit and Office 2016 32bit. After locating the key, create or change the EditFlags Binary value to 00 00 01 00.
Run as Administrator
- Hold the Shift key and right click on the shortcut you use to open Outlook.
- Choose Run as Administrator.
To use this setting for several restarts:
- In the Search field on the Start menu, type Outlook.
- Right click on Outlook and choose Properties
- Select the Compatibility tab and enable Run the programs as an Administrator
When you no longer need administrator permissions you should repeat the steps to disable Run as Administrator. Outlook is less secure when you use run as administrator and it should not be used permanently.
Edit the Registry
If you are using 32-bit Outlook on Windows 64-bit, the registry keys are now stored in a (crazy-long) path under HKEY_LOCAL_MACHINE. This is the path for 64-bit Windows and 32-bit Office:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\ DOC: Word.Document.8 DOCX: Word.Document.12 PDF: AcroExch.Document XLSX: Excel.Sheet.12 XLS: Excel.Sheet.8 PPT: PowerPoint.Show.8 PPTX: PowerPoint.Show.12 EditFlags: 00 00 01 00 (Binary Value)
If you have more than one PDF program installed, you will need to edit the keys for each PDF program.
Outlook 2016 32-bit on Windows 10 64-bit:
If you are using Windows 7 (and newer) with Office in the same bitness (both Office and Windows are 32 bit, or both are 64bit), the path is under HKEY_CLASSES_ROOT.
DOC: HKEY_CLASSES_ROOT\Word.Document.8 DOCX: HKEY_CLASSES_ROOT\Word.Document.12 PDF: HKEY_CLASSES_ROOT\AcroExch.Document XLSX: HKEY_CLASSES_ROOT\Excel.Sheet.12 XLS: HKEY_CLASSES_ROOT\Excel.Sheet.8 PPT: HKEY_CLASSES_ROOT\PowerPoint.Show.8 PPTX: HKEY_CLASSES_ROOT\PowerPoint.Show.12 HTML: HKEY_CLASSES_ROOT\htmlfile EditFlags: 00 00 01 00
To always ask before opening, either delete the EditFlags value or change the value to 00 00 00 00
See Restore (or Hide) the Open Save Dialog if you need instructions for older versions of Windows.
Identify keys for other file types
To identify other file types, look at the extension's key in the registry - most (if not all) will include a more descriptive name. Locate this name under HKEY_CLASSES_ROOT and change it's EditFlags value.
For example, this is the key for the .pptx extension (shown in the screenshots):
HKEY_CLASSES_ROOT\.ppt\PowerPoint.Show.12
So you would change the EditFlags value at HKEY_CLASSES_ROOT\PowerPoint.Show.12
The locate the key by that name. Double click on the EditFlags key to open it for editing.
00 00 00 00 displays the Open or Save dialog
00 00 01 00 opens the file.
Do it for me
If you don't want to edit the registry, you can use this Registry file. It contains the EditFlag for Word, Excel, and PowerPoint listed above plus htmlfile.
Edit Flags registry keys 32-bit Outlook on 64-bit Windows
Download the file and double click to add the keys to the registry. Note that some browsers will save it with the .txt extension. You'll need to change the extension to .reg to use.
More Information
Restore (or Hide) the Open Save Dialog Instructions for older versions of Windows.
I think many people have this issue because the default PDF handler is only partially selected. I was able to fix the issue on 2 different PCs (one Win10 standalone, the other Win7 domain-joined). Simply open Adobe Reader, go to Edit -> Preferences -> General (scroll down if needed). Click on "Set as Default PDF Handler".
To explain... on both computers, Adobe Acrobat (Reader) was set as the default action when double-clicking a PDF to launch or when opening an attachment. However, there is more than just one setting, and the registry showed the ".pdf" extension as "MSEdgePDF" which was my clue. In both cases, simply using the built-in "Set as Default" in Adobe Reader fixed the registry entry.
Great information. Way better than MS online community.
THANK YOU !
Hi Diane - Thanks for this. I've got the .docx extentions opening without hassle. ?
My PDF (and default) viewer of choice is Sumatra PDF. Sumatra doesn't appear as a key (that I can find) under HKEY_CLASSES_ROOT. (I've tried a search with F3). Also, the value name "Default" under "HKEY_CLASSES_ROOT\.pdf" is blank.
Any thoughts on how I could locate the Sumatra key?
Thanks, R.
Hi Diane.
Any more thoughts on why this problem keeps recurring? .MP4 attachments have reverted to Outlook not giving me the option to open them with a straight double-click, but rather throws at me that stupid, greyed out 'Always ask before opening...' window.
I had already 'fixed' this a few times in the past, by editing the Registry as recommended. The problem is back. The program associated with MP4 files is VLC. I have by now done the most thorough search of the Registry for any mp4, or .mp4 or VLC, and cannot find a single place where I had not already inserted the EditFlags key and its 00 00 01 00 value.
The only thing that has knowingly changed in my computer (Windows 10) setup is that, a few days ago, I installed another video viewing software (called HPC-MC x64) which 'took possession' by itself as the default for opening video files. I don't want this. Today, I reset the default app for videos as VLC, and the video attachment on the email message indeed shows the VLC icon. However, it does not open with a double-click.
Can you suggest anything? This is driving me mad!
Perfect solution, THANKS
Diane, thanks for this Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\.docx\Word.Document.12
helped me fix a problem, which was beyond me, and why MS doesnt have an option GUI to reset this i mean really...
I think Microsoft is trying to send us all on a crazy goose chase. The issue keeps recurring, after a variable period of time being fixed. But the real problem is that each time it reappears, the fix (i.e., creating or editing the EditFlags binary value to 00 00 01 00) has to be done on a different Registry key! I have already gone through all the possible locations. On a methodical basis of changing 'one variable at a time', for (e.g.) Word documents (.docx) I have had to deal with that EditFlags value at either: Computer\HKEY_CLASSES_ROOT\Word.Document, or
Computer\HKEY_CLASSES_ROOT\Word.Document.12, or Computer\HKEY_CLASSES_ROOT\.docx, or Computer\HKEY_CLASSES_ROOT\.docx\Word.Document.12, or Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\.docx, or
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\.docx\Word.Document.12
So, after this sort of trial and error, the change on one of these keys works, so I leave it there. Then, when the problem recurs (days? weeks? months? As I do not reboot the PC often, it is difficult to ascertain the interval between 'treatments'), the EditFlags value is on the original key, but it is no longer doing what it was meant to do, i.e., to allow direct opening of a Word attachment from the email.
Total mystery to me!
Does it make any sense to you, Diane? Anybody else?
There is definitely something going on - and I hope you are exporting the keys and merging them into 1 reg file so you can quickly restore the entries.
I know the run as admin trick does not work on new versions... I suspect the key with the editflags DWORD are the issue and will test to see if only changing / adding the binary key to the other keys works (and leaving the DWORDs alone).
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\.docx\Word.Document.12
didnt have the editflags, so i created it, and all is well now
Thanks, Gavin.
It is kind of you to send me a reply, but I had already tried this one as well - see the list (16 March) of all the keys where I had already created an EditFlags binary value (00 00 01 00).
And, because I sometimes also receive Word documents in the old .DOC (rather than the current .DOCX) format, I had to check and create the same EditFlags key on all those locations I listed.
However, at present, that key with the 00 00 01 00 binary value is working fine for .DOCX documents (i.e., I can open the attachment in Word directly from the email message), but... not for .DOC attachments (when I still get the annoying prompt for permission to open or save).
The whole behaviour and intermittent nature of this bug is very mysterious.
Have you done any further tests, Diane?
The location in the registry has changed for this (for me at least); it is now in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes.
My particular issue was with .wav files. Note; I have VLC player as the default program to open .wav files.
To find the default for .wav, I still had to look in HKEY_CLASSES_ROOT and find that the default was VLC.wav, but then I didn't edit the VLC.wav in this location, I edited the VLC.wav in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes. There was not an Editflags, I had to add one.
This took care of my problem!
How exactly did you add it? I'm trying to add the .oft file type and everything I seem to try is not working.
Change the edit flag here -
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Classes\Outlook.File.oft.15
(That works for 2016/2019/365 - should for for 2013 too.)
FANTASTIC! That worked. Thank you very much Diane! :-)