How the PE system letter is modified

How is the PE system letter modified? WinPE believe that everyone has used, but every time the PE letter is fixed, then there is no way to change the letter?

For example, the PE system in the B disk into the W plate, carry forward the DIY spirit, and then together to modify it. The following areas are roughly required:

First, WINPE. There is one place in the INI that needs to be modified:

Configuration file Start

Moun%curdrv%minipeop. wim,w:,1

ENVI opdir=w: External Program

Second, Winpe.is_ Core decompression, under the System32 has a setupreg.hi_, and then decompression, get Setupreg.hiv, with Registry workshop load as a registry hive WinPE, here are two to change:

[Hkey_local_machinepecontrolset001controlsession Managerenvironment]

"Path" = "%systemroot%;%systemroot%system32; W: External program Pe_outerpartmmc; W: External Programs Internet Explorer

[Hkey_local_machinepecontrolset001servicesramdrivparameters]