redhat5.2忘记系统密码,可以按以下步骤更改root密码
一.启动redhat5.2,在3秒内按方向键(↓)
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap1.jpg)
二.进入下面页面后按"E"键
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap2.jpg)
三.在页面中选第二项(kernel 开头的),按"E"键
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap3.jpg)
四.在新页面中输入"空格+single"
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap4.jpg)
五.按回车,会回到第四步的页面,按"B"键系统会重启进入single模式,在"sh-3.2#"后面输入"passwd root",回车
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap5.jpg)
六.输入新密码,加车
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap6.jpg)
七.确认输入新密码,"回车"
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap7.jpg)
八.页面会输出"passwd:all authentication tokens updated successfully"
然后在"sh-3.2#"后输入"reboot"重启系统后,密码修改完成
一.启动redhat5.2,在3秒内按方向键(↓)
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap1.jpg)
二.进入下面页面后按"E"键
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap2.jpg)
三.在页面中选第二项(kernel 开头的),按"E"键
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap3.jpg)
四.在新页面中输入"空格+single"
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap4.jpg)
五.按回车,会回到第四步的页面,按"B"键系统会重启进入single模式,在"sh-3.2#"后面输入"passwd root",回车
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap5.jpg)
六.输入新密码,加车
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap6.jpg)
七.确认输入新密码,"回车"
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap7.jpg)
八.页面会输出"passwd:all authentication tokens updated successfully"
然后在"sh-3.2#"后输入"reboot"重启系统后,密码修改完成
![](https://images.cnblogs.com/cnblogs_com/bigkangaroo/20090724linux/Snap8.jpg)