Fault symptom: it can't start normally after booting, suggesting that bootmgr is compressed.

Solution:

1, insert the system disk (if it is not running on cd-com or usb, press F 12 after booting. Then choose usb or cd-com to run). After entering the winpe system, open my computer, right-click the C disk, check the option of "compressing this disk to save space", and click OK. restart

2. Run from the system disk, open the command prompt in the system recovery selection, run two commands "Bootrec.exe/fixmbr" and "Bootrec.exe/fixbool", and then restart.