说明： 操作系统在使用过程中，随着越来越多的应用软件加载在系统中，电脑启动时间将越来越慢，即使这些加载的应用程序有很多是不必要的 (operating system in use, as more and more application software loaded in the system, the computer will boot-up time is getting slower and slower, even though they loaded applications is a lot of unnecessary)
