Restore PDF preview for files on IP-mapped network shares

Scope

Per-PC, per-user fix (no PowerShell). Applies when paths like \\26.159.157.183\... won’t preview. (replace IP)

Steps

1) Set Site-to-Zone mapping

• Open Local Group Policy Editor: Win + R → gpedit.msc

• Go to:
  User Configuration → Administrative Templates → Windows Components → Internet Explorer → Internet Control Panel → Security Page → Site to Zone Assignment List

• Enable the policy → click Show… → add these entries:

2) Force policy update

• Open Command Prompt (Admin) and run:
  gpupdate /force

Prevent new blocks:

gpedit.msc → User Configuration → Administrative Templates → Windows Components → Attachment Manager → Do not preserve zone information… = Enabled.

Clear thumbnail cache: Disk Cleanup → Thumbnails.