将以下文本保存为"PDF预览.reg",双击运行即可修复

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers]
"{3A84F9C2-6164-485C-A7D9-4B27F8AC009E}"="Microsoft PDF Previewer"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.pdf\ShellEx\{8895b1c6-b41f-4c1c-a562-0d564250836f}]
@="{3A84F9C2-6164-485C-A7D9-4B27F8AC009E}"