signed int WindowsVersionCalcnRet_sub_100C6E78()
{
  signed int result; // eax@1
  char v1; // al@2
  int v2; // ecx@2
  signed int v3; // eax@3
  char v4; // al@6

  result = dword_10256E1C;
  if ( !dword_10256E1C )
  {
    v1 = VerifyWindowsVersion_sub_100C6D36(6u, 3u, 0);
    v2 = 0;
    if ( v1 )
    {
      v3 = 0x100000;
    }
    else if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 3u, 1)
           || (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 2u, 1) )
    {
      v2 = 0;
      v3 = 0x400000;
    }
    else
    {
      v4 = VerifyWindowsVersion_sub_100C6D36(6u, 2u, 0);
      v2 = 0;
      if ( !v4 )
      {
        if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 1u, 0) )
        {
          result = 0x1000;
        }
        else if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 1u, 1)
               || (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 0, 1) )
        {
          result = 0x20000;
        }
        else if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(6u, 0, 0) )
        {
          result = 0x800;
        }
        else if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(5u, 2u, 1) )
        {
          result = 0x400;
        }
        else if ( (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(5u, 2u, 0)
               || (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(5u, 1u, 0) )
        {
          result = 0x200;
        }
        else
        {
          result = (unsigned __int8)VerifyWindowsVersion_sub_100C6D36(5u, 0, 0) != 0 ? 256 : 63;
        }
        goto LABEL_23;
      }
      v3 = 0x40000;
    }
    LOBYTE(v2) = 1;
    result = (v3 & (v2 - 1)) + v3;
LABEL_23:
    dword_10256E1C = result;
  }
  return result;
}