接着我们在打开的记事本中一字不差的输入以下代码：

Windows Registry Editor Version 5.00

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.jpg]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.jpeg]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.gif]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.png]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.bmp]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.tiff]

 @="PhotoViewer.FileAssoc.Tiff"

 ; Change Extension's File Type

 [HKEY_CURRENT_USER\Software\Classes\.ico]

 @="PhotoViewer.FileAssoc.Tiff"

（感谢网络大神提供的代码，此代码主要是为了导入注册表）

如下图所示：