桌面创建一个txt文本
复制这些命令，之后将后缀改为.reg，右击管理员身份运行即可

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"