上传到网站Server 上的某些文档格式无法下载

最近遇到网站上,用户上传了pptx 等office 2010的文档. 在后台管理中无法下载.

解决方法是网站添加MIME类型

添加扩展的方法（图示）：

进入IIS对应网站站点→右键[属性→HTTP标头→MIME类型→新建→扩展名|类型

图示列举了是以word   .docx扩展为例。
.docx        application/vnd.openxmlformats-officedocument.wordprocessingml.document

 

全套offices：
=======================================
.docm        application/vnd.ms-word.document.macroEnabled.12
.dotm        application/vnd.ms-word.template.macroEnabled.12
.dotx        application/vnd.openxmlformats-officedocument.wordprocessingml.template
.potm        application/vnd.ms-powerpoint.template.macroEnabled.12
.potx        application/vnd.openxmlformats-officedocument.presentationml.template
.ppam        application/vnd.ms-powerpoint.addin.macroEnabled.12
.ppsm        application/vnd.ms-powerpoint.slideshow.macroEnabled.12
.ppsx        application/vnd.openxmlformats-officedocument.presentationml.slideshow
.pptm        application/vnd.ms-powerpoint.presentation.macroEnabled.12
.pptx        application/vnd.openxmlformats-officedocument.presentationml.presentation
.xlam        application/vnd.ms-excel.addin.macroEnabled.12
.xlsb        application/vnd.ms-excel.sheet.binary.macroEnabled.12
.xlsm        application/vnd.ms-excel.sheet.macroEnabled.12
.xlsx        application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.xltm        application/vnd.ms-excel.template.macroEnabled.12
.xltx        application/vnd.openxmlformats-officedocument.spreadsheetml.template