How to fix PDF preview in Outlook 365?

[default5kue4kpyfpsa]

Hello,

I'm currently using the 64-bit Adobe Reader installed as App:

• C:\Program Files\WindowsApps\Adobe.Inc.Acrobat.Reader.DC_21.5.20048.0_x64__2kwj4jv5edp0w\Reader

What Values do I need to change in regedit to enable PDF preview in Outlook 365?

• Computer\HKEY_CLASSES_ROOT\.pdf

Thank you in advance.

[default5kue4kpyfpsa]

• C:\Program Files\WindowsApps\Adobe.Inc.Acrobat.Reader.DC_21.5.20048.0_x64__2kwj4jv5edp0w\Reader\AcroRd32.exe

[default5kue4kpyfpsa]

This file cannot be previewed because there is no previewer insalled for it.

[default5kue4kpyfpsa]

C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE

[Test Screen Name]

You need to install Acrobat Reader DC. Not Reader Touch. 

[default5kue4kpyfpsa]

It shows Adobe Acrobat Reader DC, Version: 21.005.20048.43252 .

In Apps and Features it shows Acrobat Reader DC, IES.

[default5kue4kpyfpsa]

Maybe my assumption was wrong that it's 64-bit.

[Test Screen Name]

Run Reader. Look in ABOUT in the usual way. It will tell you if it's 32-bit or 64-bit. But you could also see whether it's installed in Program Files or Program Files (X86). Only it looks like you installed it from the Microsoft Store. It's only been there a few days, I think, all bets are off. Personally, I'd get rid of it and install Adobe's download.

[default5kue4kpyfpsa]

These are the available context menu options for Acrobat Reader DC in Windows 10 Start menu:

I already mentioned the install location:

• C:\Program Files\WindowsApps\Adobe.Inc.Acrobat.Reader.DC_21.5.20048.0_x64__2kwj4jv5edp0w\Reader\AcroRd32.exe

Here you can see the About Screen:

Here you can see the Apps & Features entry (App-Einstellungen / App-Settings):

Erweiterte Optionen / Advanced options:

[default5kue4kpyfpsa]

In Microsoft Store I can't see Adobe Acrobat Reader entry in My library.

[default5kue4kpyfpsa]

When I open Windows 10 Settings → Default apps → Set defaults by app → Acrobat Reader DC → Manage

it shows that it has all assigned.

[default5kue4kpyfpsa]

Outlook: Problem with PDF Preview Handler - TechNet Articles - United States (English) - TechNet Wik... 

3. Making Sure That "PDF Preview Handler" is Enabled

In Outlook, navigate through “File > Options > Trust Center > Trust Center settings > Attachment Handling” and:

• Make sure that “Turn off Attachment Preview” box is unchecked.
• Click “Attachment and Document Previewers” button and check if “PDF Preview Handler” is enabled/ticked in the list in the opened window.

When I check the list it doesn't provide an PDF Preview Handler instead only an PDF-XChange Preview Handler.

How to install the PDF Preview Handler?

[default5kue4kpyfpsa]

4. Manually Creating Required Adobe Reader-related Registry Records

This is the most common cause of the problem. Adobe Reader may not have created the required registry record in 64-bit Windows or it might be corrupted. In order to fix it, you'll need to create the required registry value manually:

Key: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\CLSID\{DC6EFB56-9CFA-464D-8880-44885D7DC193}
Value name: AppID
Value type: REG_SZ
Value: {534A1E02-D58F-44f0-B58B-36CBED287C7C}

• Have a backup of the registry first. Making a mistake in registry can lead to unexpected and serious problems, so doing this beforehand is highly recommended:
  https://support.microsoft.com/tr-tr/help/322756/how-to-back-up-and-restore-the-registry-in-windows
• Copy the text below and paste it to a notepad, then save it with a name like PDFPreviewHandler.reg as a REG file:

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\CLSID\{DC6EFB56-9CFA-464D-8880-44885D7DC193}]
"AppID"="{534A1E02-D58F-44f0-B58B-36CBED287C7C}"

• Double-click on the REG file to merge it. After that, the corresponding value in registry will look like this:
• Restart your computer.

When I navigate in regedit.exe to the target key

Computer\HKEY_CLASSES_ROOT\AppID\{534A1E02-D58F-44f0-B58B-36CBED287C7C}

it shows the following entry:

Name ; Type ; Data
(Default) ; REG_SZ ; 32-bit Preview Handler Surrogate Host
DllSurrogate ; REG_EXPAND_SZ ; C:\Windows\SysWOW64\prevhost.exe


Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\AppID\{534A1E02-D58F-44f0-B58B-36CBED287C7C}]
@="32-bit Preview Handler Surrogate Host"
"DllSurrogate"=hex(2):43,00,3a,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,\
  00,5c,00,53,00,79,00,73,00,57,00,4f,00,57,00,36,00,34,00,5c,00,70,00,72,00,\
  65,00,76,00,68,00,6f,00,73,00,74,00,2e,00,65,00,78,00,65,00,00,00

[default5kue4kpyfpsa · Accepted solution]

In Windows 10 Explorer is shows an Preview of PDF files using PDF-XChange Preview Handler.

When I restarted Outlook it shows an Preview of PDF files using PDF-XChange Preview Handler.

[FlytÅge · Accepted solution]

For me, the problem was solved by changing a setting in Powertoys. Under "File Explorer add-ons", try to disable "Enable PDF (.pdf) preview"

[BruteL]

Thank you, Åge! Have been googling all over the place and have been looking at all kinds of suggested reg. edit. fixes reg., but my registry was fine. Disabled Enable PDF preview in Power Toys and just like that I was able to preview my PDFs in Outlook again! (Updated Power Toys today to 0.56.2 - the update must have changed a setting or messed something up.)

[adwul62]

From me as well: THANK you very much. Have been struggling with this for many hours, in the end even including full uninstall (incl. registry settings, etc.) and re-install. Nothing worked. Your solution did. Again thanks!!

[BabakBani]

Thank you! This was the solution for the problem that has been plaguing our business machines for months!!

I expected it was an update that Microsoft put out for Outlook 365 that broke the preview handler functionality. 

The culprit all along was MS PowerToys. 

I reposted your solution with back reference to:

1) Outlook 365 support group: https://answers.microsoft.com/en-us/outlook_com/forum/all/outlook-365-not-showing-pdf-preview/c30ca3...

2) Reddit, Outlook group: https://www.reddit.com/r/Outlook/comments/tkod6y/having_trouble_previewing_pdfs_in_outlook_365/

3) MS PowerToys Github, filed an issue: https://github.com/microsoft/PowerToys/issues/17221

Thank you!

[FlytÅge]

This has been a nightmare for me. I'm glad I could contribute to solve your problem as well. 

[stu502]

Thank you, has been bugging me for ages too! Finally got sick of it and started looking for solutions again, just did a full reinstall then found this.

Great work!

[Chris NN]

I thought I was going to tear my hair out. No other solution was working. Thank you!

[Peter25227529uepn]

In Outlook, navigate through “File > Options > Trust Center > Trust Center settings > Attachment Handling” and:
- Make sure that the “Turn off Attachment Preview” box is unchecked.
- Click the “Attachment and Document Previewers” button and check if “PDF Preview Handler” is enabled/ticked in the list in the opened window.

Regards,

Peter

[Damien27125879ck9e]

I check it and “PDF Preview Handler” is enabled but i have 2 “PDF Preview Handler” ....
it doesn't work :'(

[ageped]

Disable "Enable PDF (.pdf) preview"