@echo off
set P1=%USERNAME%@%COMPUTERNAME%

if "%PROCESSOR_ARCHITECTURE%" == "AMD64" (
    set P2= x64 $P
) else (
    set P2= x86 $P
)

net session >nul 2>&1
if %errorLevel% == 0 (
  set P3=$$
) else (
  set P3=$G
)

set P4= 

prompt %P1%%P2%%P3%%P4%