1. 出错提示：
启动xampp出错，Port 80 in use by "Unable to open process" with PID 4!
环境：windows Server 2008
2. 解决方案：
Simply set Apache to listen on a different port. This can be done by clicking on the "Config" button on the same line as the "Apache" module, select the "httpd.conf" file in the dropdown, then change the "Listen 80" line to "Listen 8099". Save the file and close it.
Now it avoids Port 80 and uses Port 8080 instead without issue. The only additional thing you need to do is make sure to put localhost:8080 in the browser so the browser knows to look on Port 8080. Otherwise it defaults to Port 80 and won't find your local site.
（2） 操作步骤：
config->Service and Port Settings ->Apache -> Main Port ->改为8099