安装tomcat时提示 Failed to install Tomcat7 service
应该是卸载时直接删除目录导致的.
Failed to install Tomcat7 service Check your settings and permissions Ignore and continue anyway (not recommended)?
Alt+R(开始->运行) services.msc
查看Apache Tomcat 7.0 Tomcat7对应的服务名
然后以管理员身份(桌面右击点击菜单Open CMD)运行命令提示符（cmd），执行
sc delete Tomcat7 命令
这样就可以了