Windows explorer stops showing PDF's in the preview pane

Solution 1:

This issue occurs because you must open another instance of the program to preview the document.

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Modules\GlobalSettings\DetailsContainer]
"DetailsContainer"=hex:02,00,00,00,01,00,00,00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Modules\GlobalSettings\Sizer]
"DetailsContainerSizer"=hex:24,01,00,00,01,00,00,00,00,00,00,00,2b,03,00,00

Then do the following for both keys:

• Right click the key
• Select Permissions
• Select your name
• Check Deny

References

• Solution to Windows 7 Preview Pane Size Problem
• How to set different Windows 7 Explorer layouts for different windows (with/without navigation pane)
• How to Register a Preview Handler
• The Complete Idiot's Guide to Writing Shell Extensions
• Acrobat Pro X PDF previewing not working in Windows 7 64-bit
• Acrobat Preview Handler Windows Server 2012
• How to Enable the Preview of PDF Files in 64-bit Windows 7
• Why doesn't PDF Preview Handler Work?
• PDF and XFDF file associations
• Thumbnails Missing in Vista Explorer Large & Extra Large View
• PDF Icons used to Show Preview of Document - Now it shows PDF Icon
• Acrobat Cleaner
• Known issues | Acrobat XI, Reader XI

Solution 2:

When the preview suddenly stops working (but has worked in the past)... Use Ctrl-Alt-Delete to start the Task Manager. Click on the Processes tab. End the "AcroRd32" processes (close Acrobat processes). Click on a new pdf in Windows explorer and it should now show up in the preview.