Detect XP In VirtualPC 2007 (Resume Flag Trick)

//http://waleedassar.blogspot.com
//http://www.twitter.com/waleedassar
//Use this code to detect if Windows XP is running inside Virtual PC 2007
#include "stdafx.h"
#include "windows.h"
#include "stdio.h"

#define CONTEXT_ALL 0x1003F

int dummy(int);
unsigned long gf=0;
int __cdecl Handler(EXCEPTION_RECORD* pRec,void* est,unsigned char* pContext,void* disp)
{
    if(pRec->ExceptionCode==0xC0000096)  //Privileged instruction
    {
        //---------------------Installing the trick--------------------------------------
        *(unsigned long*)(pContext)=CONTEXT_ALL;/*CONTEXT_DEBUG_REGISTERS|CONTEXT_FULL*/
        *(unsigned long*)(pContext+0x4)=(unsigned long)(&dummy);
        *(unsigned long*)(pContext+0x8)=(unsigned long)(&dummy);
        *(unsigned long*)(pContext+0xC)=(unsigned long)(&dummy);
        *(unsigned long*)(pContext+0x10)=(unsigned long)(&dummy);
        *(unsigned long*)(pContext+0x14)=0;
        *(unsigned long*)(pContext+0x18)=0x155; //Enable the four DRx On-Execute
        //---------------------------------------------------------------------------------
        (*(unsigned long*)(pContext+0xB8))++;
        return ExceptionContinueExecution;
    }
    else if(pRec->ExceptionCode==EXCEPTION_SINGLE_STEP)
    {
        if(gf==1)
        {
               MessageBox(0,"Expected behavior (XP)","waliedassar",0);
               ExitProcess(0);
        }
        gf++;
        (*(unsigned long*)(pContext+0xC0))|=0x00010000; //Set the RF (Resume Flag)
        return ExceptionContinueExecution;
    }
    return ExceptionContinueSearch;
}

int dummy(int x)
{
    x+=0x100;
    return x;
}

int main(int shitArg)
{
    unsigned long ver_=GetVersion();
    unsigned long major=ver_&0xFF;
    unsigned long minor=(ver_>>0x8)&0xFF;
    if(major==0x05 & minor==0x01) //Windows XP
    {
        unsigned long x=0;
        __asm
        {
           push offset Handler
           push dword ptr fs:[0x0]
           mov dword ptr fs:[0x0],esp
           STI; Triggers an exception(privileged instruction)
        }
        dummy(0xFF);
        __asm
        {
            pop dword ptr fs:[0x0]
            pop ebx
        }
        MessageBox(0,"Virtual PC 2007 detected (XP)","waliedassar",0);
    }
    return 0;
}