MBR to GPT conversion

This will run the MBR2GPT tool's validation before attempting conversion:

@ECHO OFF
MBR2GPT.EXE /validate
IF %ERRORLEVEL% NEQ 0 GOTO ERROR

MBR2GPT.EXE /convert
IF %ERRORLEVEL% NEQ 0 GOTO ERROR

:ERROR
EXIT /B %ERRORLEVEL%