问题描述：
404 - File or directory not found.
The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.
这个问题在平时发布网站时经常出现，可是sharepoint的机制却有所不同。在它所安装的local machine上可以打开所有的site collections网站和administrator site网站。而在其他的mechine上却不能打开site collections网站，只能打开administrator site网站。用过sharepoint 的人都知道这是因为两种网站在不同的server上。但是在其他的machine上为什么不能打开site collections网站，只能local machine打开呢？
解决方法：
1. 检查IIS路径，问题依旧
2. 重启IIS和Application pool，问题依旧
3. 重启计算机，问题依旧
4. 更改站点名称，问题依旧
5. 检查Log, C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\LOGS，发现报错信息：High Error initializing Safe control - Assembly:Microsoft.Office.SharePoint.ClientExtensions
有关系吗？--没关系。
最终，发现另外一个同事居然在IIS上新建了一个站点和sharepoint -80相冲突。真够悲剧的，花了一个下午啊。。。怎么SharePoint端口被侵占也不吭一声呢。。。
Issue:Today,we can’t open the sharepoint site collections from Internet suddenly ,but we can open them in the server machine. so i tried to restart iis ,check the vitual directory,restart server and rename the website name, but it still can't work.
Reason: the port for "sharepoint-80" is used by other site.
