[Fix] PDF Thumbnail and Preview Not Showing Up in File Explorer

In your Windows computer, File Explorer may not display PDF thumbnails, and instead, show only the default icon assigned for PDF files. This might happen even if you have the option Always show icons, never thumbnails unchecked in the View tab of the Folder Options dialog.

Also, in Microsoft Outlook you’ll see the error when viewing emails that contain PDF file attachments:

The file cannot be previewed because there is no previewer installed for it

This article tells you how to enable PDF thumbnails as well as the PDF preview capability (for the Preview pane) in File Explorer and Microsoft Outlook. The first method (PowerToys) works whether or not you’re using a third-party PDF viewer (e.g., Adobe PDF Reader or Foxit Reader).

[Fix] PDF Thumbnail and Preview Not Showing in Explorer

Preliminary step – Enable thumbnails and preview handlers in Explorer

1. Open Folder Options
2. Enable “Show preview handlers in preview pane”
3. Uncheck “Always show icons, never thumbnails”
   
4. Click OK and close Folder Options.

If thumbnail and preview functionality is still missing for PDF file types, proceed to the next step.

Using Microsoft PowerToys

Microsoft PowerToys is a set of utilities for power users to tune and streamline their Windows 10 experience for greater productivity. PowerToys requires Windows 11 or Windows 10 v1903 (18362) or newer to work.

You can use Microsoft PowerToys to enable PDF thumbnails and preview generation (for the preview pane) even if you don’t have a proprietary PDF viewer software installed. There is no 32-bit version of Microsoft PowerToys; only the 64-bit version has been released.

PowerToys includes a PDF thumbnail generator as well as the preview handler module (DLL). Thus, it works even if you’re using the Windows default PDF viewer (Microsoft Edge browser) for opening PDF files.

To enable thumbnail generation and preview capabilities for PDF files:

1. Download Microsoft PowerToys via the Microsoft Store.
2. Launch Microsoft PowerToys as administrator (Run as administrator)
3. In PowerToys Settings, select “File Explorer add-ons” in the left pane.
   
4. Turn on the “Enable PDF (.pdf) preview” setting.
5. Turn on the “Enable PDF (.pdf) thumbnails” setting.
6. Close or minimize Microsoft PowerToys.

Note: PowerToys need not be running in the background in order for the PDF preview and thumbnail feature to work. You can exit PowerToys if you want.

Here you go! The thumbnails and preview pane capability for PDF files are now restored.

Preview handler for PDF files
GUID: {07665729-6243-4746-95b7-79579308d1b2}
Filename: C:\Program Files\PowerToys\modules\FileExplorerPreview\PowerToys.PdfPreviewHandler.comhost.dll

Thumbnail generator for PDF files
GUID: {BCC13D15-9720-4CC4-8371-EA74A274741E}
Filename: C:\Program Files\PowerToys\modules\FileExplorerPreview\PowerToys.PdfThumbnailProvider.comhost.dll

Fix For Outlook Users

There is an additional step needed to enable the PowerToys preview handler in Outlook.

Open an admin Command Prompt window and run this command:

reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers" /v "{07665729-6243-4746-95b7-79579308d1b2}" /d "Pdf Preview Handler" /t REG_SZ

Outlook 32-bit Registry Fix (for Microsoft PowerToys users)

Microsoft PowerToys is a 64-bit program. So, its PDF preview handler above won’t be listed in the Outlook 32-bit Trust Center settings as the WOW6432Node registration would be missing by default and also causes the following error in Microsoft Outlook 32-bit:

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

To make the PowerToys’s PDF preview handler work in Outlook 32-bit, you need to apply the following registry fix. Once done, it gets listed in the Trust Center settings and you should be able to preview PDF attachments in your email.

Windows Registry Editor Version 5.00

;Microsoft PowerToys PDF Preview Handler Fix for Outlook 32-bit

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\PreviewHandlers]
"{07665729-6243-4746-95b7-79579308d1b2}"="Pdf Preview Handler"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{07665729-6243-4746-95b7-79579308d1b2}]
"DisplayName"="Pdf Preview Handler"
@="Microsoft.PowerToys.PreviewHandler.Pdf.PdfPreviewHandler"
"AppID"="{6d2b5079-2f0b-48dd-ab7f-97cec514d30b}"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{07665729-6243-4746-95b7-79579308d1b2}\Implemented Categories]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{07665729-6243-4746-95b7-79579308d1b2}\Implemented Categories\{62C8FE65-4EBB-45E7-B440-6E39B2CDBF29}]
@=""

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{07665729-6243-4746-95b7-79579308d1b2}\InprocServer32]
@="C:\\Program Files\\PowerToys\\modules\\FileExplorerPreview\\PowerToys.PdfPreviewHandler.comhost.dll"
"Assembly"="PowerToys.PdfPreviewHandler, Version=v0.53.1.0, Culture=neutral"
"Class"="Microsoft.PowerToys.PreviewHandler.Pdf.PdfPreviewHandler"
"ThreadingModel"="Both"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{07665729-6243-4746-95b7-79579308d1b2}\InprocServer32\v0.53.1.0]
"Assembly"="PowerToys.PdfPreviewHandler, Version=v0.53.1.0, Culture=neutral"
"Class"="Microsoft.PowerToys.PreviewHandler.Pdf.PdfPreviewHandler"

To apply the above registry fix:

1. Copy the above lines to Notepad.
2. Save the file as PreviewFix.reg.
3. Double-click the file to run it.
4. Click Yes (when prompted) to apply the settings.

The above registry fix resolves the error “This file cannot be previewed because there is no previewer installed for it” in Microsoft Outlook when Microsoft PowerToys’s PDF preview handler is enabled.

(For more information about registry files, check out the article How to use .REG files (Registration Entries) in Windows.)

Using Adobe Acrobat Reader

Adobe Acrobat Reader includes the thumbnail extractor as well as a preview handler shell extension which generates PDF thumbnails as well as file preview in the Preview pane in File Explorer. PDF thumbnails can be enabled or disabled via Adobe Reader’s Preferences dialog.

Enable or Disable PDF “Thumbnails” in File Explorer via Adobe Preferences

Open Adobe Reader, click Edit, Preferences. Under “General”, enable the option Enable PDF thumbnail previews in Windows Explorer.

Note: If you’ve chosen to disable PDF thumbnails, existing PDF files may still show thumbnail preview from the cache. The thumbnail cache needs to cleared using Disk Cleanup.

Enable or Disable PDF “Preview” in Explorer Preview pane

When you install (or reinstall) Adobe Acrobat Reader DC, the thumbnail extractor, as well as the Preview handler, are registered automatically.

To disable PDF file preview in the File Explorer preview pane, use these steps:

1. Launch Regedit.exe and navigate to the following branch:

   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers

2. From the File menu, choose Export… and backup the branch to a REG file.
3. Right-click the GUID for Adobe PDF Preview Handler which is usually {DC6EFB56-9CFA-464D-8880-44885D7DC193} and choose Delete.
4. Click Yes when asked for confirmation.
5. Exit the Registry Editor.
6. Log off and login back for the change to take effect.

To enable PDF Preview handler, add the value {DC6EFB56-9CFA-464D-8880-44885D7DC193} back or merge the REG file you backed up in Step 4 above.

Automate Using REG Files

To automate enabling or disabling PDF previews as well as PDF thumbnails in File Explorer, you can use these .REG files. Download pdf-thumb-preview.zip, unzip, and extract the files to desktop. Run the appropriate REG file to enable or disable PDF thumbnails, enable or disable PDF preview in File Explorer Preview pane.

As an alternative to manual registry editing, you can use the Preview Handler Association Editor to enable or disable preview for certain file types.

Using Foxit Reader

If you’re using Foxit PDF Reader, re-run the Foxit installer, choose Custom setup and then and enable “Shell extensions” during setup.

Enabling “Shell Extensions” ensures that the Foxit preview/thumbnail extractor module (DLLs) are installed.

Foxit PDF Thumbnail Handler
GUID: {21F5E992-636E-48DC-9C47-5B05DEF82372}
Filenames:
C:\Program Files (x86)\Foxit Software\Foxit PDF Reader\Shell Extensions\FoxitThumnailsHndir.dll"  [32-bit]
(or)
C:\Program Files (x86)\Foxit Software\Foxit PDF Reader\Shell Extensions\FoxitThumbnailHndlr_x64.dll  [64-bit]

Foxit PDF Preview Handler
GUID: {1B96FAD8-1C10-416E-8027-6EFF94045F6F}
Filenames:
"C:\Program Files (x86)\Foxit Software\Foxit PDF Reader\Shell Extensions\FoxitPreviewhost.exe"
"C:\Program Files (x86)\Foxit Software\Foxit PDF Reader\Shell Extensions\FoxitPrevHndlr.dll"

For more information, check out Foxit’s official documentation PDF previews are shown as icons instead of thumbnails in Explorer, and PDF previews are not shown as thumbnails in File Explorer.

The official documentation tells you how to register the Foxit thumbnail handler shell extension FoxitThumnailsHndlr.dll or FoxitThumbnailHndlr_x64.dll (which Foxit setup does it automatically, anyway). Please note that you’ll always need to use the administrator Command Prompt to register DLL files.

Using SumatraPDF

SumatraPDF, a freeware PDF viewer, ships with a module that can generate thumbnails as well as previews for PDF files. You need to enable the following option when installing the software:

Let Windows show previews of PDF documents

Enabling the option would register the following SumatraPDF thumbnail & preview generator DLL automatically:

SumatraPDF Preview (*.pdf)
GUID: {3D3B1846-CC43-42AE-BFF9-D914083C2BA3}
Filename: C:\Users\%username%\AppData\Local\SumatraPDF\PdfPreview.dll

Using Microsoft Edge Chromium

Microsoft Edge now (probably since the February/March 2022 release) includes a built-in preview handler module named “PdfPreviewHandler.dll” (“Microsoft PDF Previewer”) located in the following directory:

C:\Program Files (x86)\Microsoft\Edge\Application\nn.n.nnnn.nn\PdfPreview\PdfPreviewHandler.dll

Microsoft Edge (Chromium) reinstall/update process should set the above PDF preview handler as the default. If not, you can set it manually by running the following command from an admin Command Prompt window:

reg add HKCR\.pdf\shellex\{8895b1c6-b41f-4c1c-a562-0d564250836f} /ve /d "{3A84F9C2-6164-485C-A7D9-4B27F8AC009E}" /f

Here you go! The PDF preview generated by Microsoft Edge’s preview handler.

Note: Microsoft Edge PDF previewer has a crazy bug where it throws the “File not found” error if the file or folder name contains the # symbol. Microsoft Edge’s current version is 101.0.1210.32 as of this post, and the issue is still unresolved. This problem is covered in the article PDF Preview Shows Directory Index or ERR_FILE_NOT_FOUND

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\SOFTWARE\Classes\.pdf\shellex\{BB2E617C-0920-11d1-9A0B-00C04FC2D6C1}]
@="{F9DB5320-233E-11D1-9F84-707F02C10627}"

Hopefully, one of the above tips or programs should fix the File Explorer PDF thumbnail and preview pane issues in Windows and Microsoft Outlook/Outlook 365.