为什么会这样？

不会吧，在浏览器菜单里，工具-->文件夹选项-->查看，
有个“隐藏已知文件的扩展名”选项

解决方案 »

  1.   

    在程序中操作注册表
    const
      KeyName = '\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced';
    var  Key  : TRegistry;
         i: integer;
    begin
       Key := TRegistry.Create;
       Key.RootKey := HKEY_CURRENT_USER;
       If Key.OpenKey(KeyName,False) then begin
          i := key.readInteger('HideFileExt');//取得当前的设置值
          Key.Write('HideFileExt',1-i); //开关设置，是1则变0，是0则变1
       end else
          ShowMessage('打不开主键!');
       Key.Free;
    end;
      

  2.   

    可以自己写代码来对注册表操作，也可以写注册表文件导入    打开资源管理器-->点击查看（Win 98/ME/IE5）或工具（Win95/IE4）-->文件夹选项-->查看选项卡，在这里提供有高级设置，不过其中的设置似乎并不能满意那些喜欢个性化的朋友。下面大家就和我们一起来为高级设置增加更多的选项，比如：视觉设置、工具栏、开始菜单、声音、鼠标、图标缓存等。好了，请下载我们这里提供的注册表文件--ADVANCED.REG（下载后解压缩至任意文件夹中），然后又击将其添加到注册表中。现在再执行最初的步骤到查看选项卡，是不是发现高级设置中增加了一大堆新东东？！只有一点比较令人遗憾，那就是Windows中文版的用户会发现这里显示的文字都是英文的（不过，使用起来没有任何问题）。
    ;------汉化：Kingron--------------
    REGEDIT4[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced][HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder]
    "Type"="group"
    "Text"="文件和文件夹"
    "Bitmap"="C:\\WINDOWS\\SYSTEM\\SHDOC401.DLL,4"
    "HelpID"="update.hlp#51140"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\Hidden]
    "Text"="隐藏文件"
    "Type"="group"
    "Bitmap"="C:\\WINDOWS\\SYSTEM\\SHDOC401.DLL,4"
    "HelpID"="update.hlp#51131"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\Hidden\SHOWALL]
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "Text"="显示所有文件"
    "Type"="radio"
    "CheckedValue"=dword:00000001
    "ValueName"="Hidden"
    "DefaultValue"=dword:00000000
    "HKeyRoot"=dword:80000001
    "HelpID"="update.hlp#51105"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\Hidden\NOHIDDEN]
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "Text"="不显示隐藏文件"
    "Type"="radio"
    "CheckedValue"=dword:00000002
    "ValueName"="Hidden"
    "DefaultValue"=dword:00000000
    "HKeyRoot"=dword:80000001
    "HelpID"="update.hlp#51104"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\Hidden\NOHIDORSYS]
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "Text"="不显示隐藏文件或系统文件"
    "Type"="radio"
    "CheckedValue"=dword:00000000
    "ValueName"="Hidden"
    "DefaultValue"=dword:00000000
    "HKeyRoot"=dword:80000001
    "HelpID"="update.hlp#51103"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\Hidden\NOHIDDEN',ValueName,,Hidden]
    @=""[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\DontPrettyPath]
    "Type"="checkbox"
    "Text"="允许所有的大写名称"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="DontPrettyPath"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000000
    "HelpID"="update.hlp#51072"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\ShowInfoTip]
    "Type"="checkbox"
    "Text"="鼠标指向文件夹和桌面项时显示提示信息"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="ShowInfoTip"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000001
    "HelpID"="update.hlp#51102"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\MapNetDrvBtn]
    "Type"="checkbox"
    "Text"="在工具栏上显示“映射”(网络驱动器)按钮"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="MapNetDrvBtn"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000000
    "HelpID"="update.hlp#51070"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\HideFileExt]
    "Type"="checkbox"
    "Text"="隐藏已知文件类型的扩展名"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="HideFileExt"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000001
    "HelpID"="update.hlp#51101"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\ShowFullPath]
    "Type"="checkbox"
    "Text"="在标题栏中显示完整路径"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\CabinetState"
    "ValueName"="FullPath"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000000
    "HelpID"="update.hlp#51100"
      

  3.   

    [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Folder\ClassicViewState]
    "Type"="checkbox"
    "Text"="记忆每个文件夹的视图设置"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="ClassicViewState"
    "CheckedValue"=dword:00000000
    "UncheckedValue"=dword:00000001
    "DefaultValue"=dword:00000000
    "HelpID"="update.hlp#51076"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual]
    "Type"="group"
    "Text"="可视设置"
    "Bitmap"="C:\\WINDOWS\\SYSTEM\\SHDOC401.DLL,6"
    "HelpID"="iexplore.hlp#50041"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\DragFullWin]
    "Type"="checkbox"
    "Text"="拖动时显示窗口内容"
    "HKeyRoot"=dword:80000001
    "RegPath"="Control Panel\\Desktop"
    "ValueName"="DragFullWindows"
    "CheckedValue"="1"
    "UncheckedValue"="0"
    "DefaultValue"="1"
    "SPIAction"=dword:00000025
    "HelpID"="update.hlp#51074"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\FontSmooth]
    "Type"="checkbox"
    "Text"="平滑屏幕字体边缘"
    "HKeyRoot"=dword:80000001
    "RegPath"="Control Panel\\Desktop"
    "ValueName"="FontSmoothing"
    "CheckedValueNT"="2"
    "CheckedValueW95"="1"
    "UncheckedValue"="0"
    "DefaultValue"="0"
    "SPIAction"=dword:0000004b
    "SPIParamON"=dword:00000002
    "HelpID"="update.hlp#51073"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\HideIcons]
    "Type"="checkbox"
    "Text"="按 Web 页显示桌面时隐藏图标"
    "HKeyRoot"=dword:80000001
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced"
    "ValueName"="HideIcons"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"="0"
    "HelpID"="update.hlp#51106"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\SmoothScroll]
    "RegPath"="Control Panel\\desktop"
    "Text"="平滑滚动"
    "Type"="checkbox"
    "CheckedValue"=dword:00000001
    "UncheckedValue"=dword:00000000
    "DefaultValue"=dword:00000001
    "ValueName"="SmoothScroll"
    "HKeyRoot"=dword:80000001
    "HelpID"="iexplore.hlp#50107"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\MinAnim]
    "RegPath"="Control Panel\\desktop\\WindowMetrics"
    "Text"="动画显示关闭和打开窗口"
    "Type"="checkbox"
    "CheckedValue"="1"
    "UncheckedValue"="0"
    "DefaultValue"="1"
    "ValueName"="MinAnimate"
    "HKeyRoot"=dword:80000001
    "HelpID"="iexplore.hlp#50107"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\DragWin]
    "Type"="checkbox"
    "Text"="在移动窗口时显示窗口内容"
    "HKeyRoot"=dword:80000001
    "RegPath"="Control Panel\\Desktop"
    "ValueName"="DragFullWindows"
    "CheckedValue"="1"
    "UncheckedValue"="0"
    "DefaultValue"="1"
    "SPIAction"=dword:00000025
    "HelpID"="update.hlp#51074"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\ToolTip]
    "RegPath"="Control Panel\\desktop"
    "Text"="显示桌面项目信息提示"
    "Type"="checkbox"
    "CheckedValue"=dword:00000080
    "UncheckedValue"=dword:00000000
    "ValueName"="UserPreferenceMask"
    "DefaultValue"=dword:00000080
    "HKeyRoot"=dword:80000001
    "Mask"=dword:00000080
    "HelpID"="iexplore.hlp#50184"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\ComboBox]
    "RegPath"="Control Panel\\desktop"
    "Text"="组合框动画"
    "Type"="checkbox"
    "CheckedValue"=dword:00000008
    "UncheckedValue"=dword:00000000
    "ValueName"="UserPreferenceMask"
    "DefaultValue"=dword:00000008
    "HKeyRoot"=dword:80000001
    "Mask"=dword:00000008
    "HelpID"="iexplore.hlp#50184"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\Visual\ListBox]
    "RegPath"="Control Panel\\desktop"
    "Text"="列表框动画"
    "Type"="checkbox"
    "CheckedValue"=dword:00000010
    "UncheckedValue"=dword:00000000
    "ValueName"="UserPreferenceMask"
    "DefaultValue"=dword:00000010
    "HKeyRoot"=dword:80000001
    "Mask"=dword:00000010
    "HelpID"="iexplore.hlp#50184"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\AutoPlay]
    "Text"="自动播放"
    "Type"="group"
    "Bitmap"="shell32.dll,12"
    "HelpID"="iexplore.hlp#50041"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\AutoPlay\Unknown]
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer"
    "Text"="未知驱动器"
    "Type"="checkbox"
    "CheckedValue"=dword:00000000
    "UncheckedValue"=dword:00000001
    "ValueName"="NoDriveTypeAutoRun"
    "DefaultValue"=dword:00000000
    "HKeyRoot"=dword:80000001
    "Mask"=dword:00000001
    "HelpID"="iexplore.hlp#50184"[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\Advanced\AutoPlay\RootDir]
    "RegPath"="Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer"
    "Text"="根目录"
    "Type"="checkbox"
    "CheckedValue"=dword:00000000
    "UncheckedValue"=dword:00000002
    "ValueName"="NoDriveTypeAutoRun"
    "DefaultValue"=dword:00000002
    "HKeyRoot"=dword:80000001
    "Mask"=dword:00000002
    "HelpID"="iexplore.hlp#50184"