们运行软件时经常会遇到以下情况，有的软件在一台机器上安装后就不能将其拷贝到其他机器上运行；有的软件甚至连原来机器的软、硬件配置改变后也无法再次运行。其实这些情况有的是利用CMOS对软件加密来实现的。安装软件时，通过安装程序把软件安装到硬盘上，同时把当前机器的CMOS信息保存到安装软盘上，也就是相当于保存了密钥。等到以后在硬盘上运行该软件时，软件的主程序会把记录在安装盘上的密钥与正在运行该软件机器的CMOS信息进行比较，如果完全相同，则允许软件继续运行，否则终止软件运行。国内的许多软件都是采用此原理进行加密的。 -software running when they often encounter the following, some software in a machine after the installation can not be copied to other machines running; some software even the original machine the software and hardware configuration change can not run again. In fact, some of these CMOS right encryption software to achieve. Installation of the software, through the installation procedure to install the software on the hard drive, while the current machines CMOS information stored on the floppy installation, which is equivalent to preserve the key. Wait until later in the drive to run the software, the software will be recorded in the main program was installed on the key and the software is running machines CMOS information, If identical, the software will allow the continued operation, oth