Pick Installing Windows 7/8 in PE

1. Use the WinPE USB boot disk to enter the computer.
2. format C drive, C drive must be active (active state).
3. Extract the Win8 ISO file to D:/win8

4. Copy from the extracted file: Bootmgr boot (entire folder) Sources/boot.wim (under C-Drive directory structure) to C-drive
5. Turn on DOS, enter: C:\boot\bootsect.exe/nt60 C: When you see a successfully word, it means success.
6. Unplug the WinPE USB drive, turn off the DOS window, and restart the computer (note the restart after the first pull)
7. The system will enter the WIN8 installation interface, do not click "Install Now", click "Repair" under the left, then click: Tool--......., finally find the DOS window to open

8. Enter D:/win8/sources (remember that it is the sources directory, not the root directory), enter: Setup.exe (it is important to use the Setup.exe under sources instead of the root directory Setup.exe, Using the root directory, there will be problems that the media driver cannot find.)
9. Normal installation

Source: http://www.2cto.com/os/201301/183260.html