系统还原点
即在指定的日期和时间内收集重要系统文件（如驱动程序、注册表、系统文件、已安装程序等），可用于将计算机还原到该位置。
create system Restore Point
- find “my computer”,right click.
- click "property"
- clisk"Advanced System Settings"
- click "system protect"
- clisk"create(C)"
- input the name of system restore piont,click"create(C)"
Restore system
- find “my computer”,right click.
- click "property"
- clisk"Advanced System Settings"
- click "system Restore(S)"
- clisk"Next Page"
- choose a system