Edit C:\Windows\PolicyDefinitions\Thumbnails.admx

??<?xml version="1.0" encoding="utf-8"?>

<policyDefinitions xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" revision="1.0" schemaVersion="1.0" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
  <policyNamespaces>
    <target prefix="thumbnails" namespace="Microsoft.Policies.Thumbnails" />
    <using prefix="windows" namespace="Microsoft.Policies.Windows" />
    <using prefix="products" namespace="Microsoft.Policies.Products" />
  </policyNamespaces>
  <resources minRequiredRevision="1.0" />
  <policies>
    <policy name="DisableThumbnails" class="User" displayName="$(string.DisableThumbnails)" explainText="$(string.DisableThumbnails_Help)" key="Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" valueName="DisableThumbnails">
      <parentCategory ref="windows:WindowsExplorer" />
      <supportedOn ref="windows:SUPPORTED_WindowsVista" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>
    <policy name="DisableThumbnailsOnNetworkFolders" class="User" displayName="$(string.DisableThumbnailsOnNetworkFolders)" explainText="$(string.DisableThumbnailsOnNetworkFolders_Help)" key="Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" valueName="DisableThumbnailsOnNetworkFolders">
      <parentCategory ref="windows:WindowsExplorer" />
      <supportedOn ref="windows:SUPPORTED_WindowsVista" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>
    <policy name="DisableThumbsDBOnNetworkFolders" class="User" displayName="$(string.DisableThumbsDBOnNetworkFolders)" explainText="$(string.DisableThumbsDBOnNetworkFolders_Help)" key="Software\Policies\Microsoft\Windows\Explorer" valueName="DisableThumbsDBOnNetworkFolders">
      <parentCategory ref="windows:WindowsExplorer" />
      <supportedOn ref="products:MicrosoftWindowsVista_SP1" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>
  </policies>
</policyDefinitions>

Ms-Dos/Windows Unix Write backup

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