Centos repair grub

Recently, centos was installed on a USB flash drive. However, grub was accidentally installed on a USB flash drive during the installation process, and then started from the USB flash drive every time. Of course, this cannot be tolerated, the following describes how to fix GRUB:

After the USB flash drive is booted into the system

[Root @ localhost/] # sbin/GRUB # enter the grub Command Line Mode

Grub> Find/boot/GRUB/stage1 find/GRUB/stage1 find
Stage1 # input the following three commands in the command line. One of the following statements returns a correct grub location.

Grub> Find/GRUB/stage1

Find/GRUB/stage1

(Hd1, 1)

Returns the location of the grub boot. At this time, DF-K can be executed.
Check that the system disk is hd0. the Linux drive letter and the drive letter in grub correspond to the relational network. Then, install grub of centos to MBR and restart.
Run:

Root (hd0, 1)
Setup (hd0)
Reboot

Modify (hd1, 1) in grub. conf and menu. lst to (hd0, 1)

Restart to enter centos