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hDC := DllCall("CreateDC", "Str", "DISPLAY", "UInt", 0, "UInt", 0, "UInt", 0)
colorBGR := DllCall("GetPixel", "UInt", hDC, "Int", x + offsetX, "Int", y + offsetY)
DllCall("DeleteDC", "UInt", hDC)

int MessageBox(
  HWND hWnd,
  LPCTSTR lpText,
  LPCTSTR lpCaption,
  UINT uType
);

DllCall("MessageBox"                 ; Name of the function
   ,"Uint",0                         ; Handle of owner window, 0 means no owner.
   ,"Str","This is some text."       ; Message box text
   ,"Str","Title!"                   ; Message box title
   ,"Uint",0)                        ; Options

DllCall("kernel32.dll\GlobalMemoryStatus", "uint",&memorystatus)
mem:=*(&memorystatus+4) ; LS byte is enough, mem = 0..100

DllCall("kernel32.dll\GlobalMemoryStatus"
       ,"uint",&memoryusage
       ,"uint",&availphys
       ,"unit",&totalpagefile)

msgbox % &memoryusage
msgbox % &availphys
msgbox % &totalpagefile

/*
typedef struct _MEMORYSTATUS {
  DWORD dwLength;
  DWORD dwMemoryLoad;
  SIZE_T dwTotalPhys;
  SIZE_T dwAvailPhys;
  SIZE_T dwTotalPageFile;
  SIZE_T dwAvailPageFile;
  SIZE_T dwTotalVirtual;
  SIZE_T dwAvailVirtual;
} MEMORYSTATUS,
 *LPMEMORYSTATUS;

dwLength
    The size of the MEMORYSTATUS data structure, in bytes. You do not need to set this member before calling the GlobalMemoryStatus function; the function sets it.
dwMemoryLoad
    A number between 0 and 100 that specifies the approximate percentage of physical memory that is in use (0 indicates no memory use and 100 indicates full memory use).
        Windows NT:  Percentage of approximately the last 1000 pages of physical memory that is in use.
dwTotalPhys
    The total size of physical memory, in bytes.
dwAvailPhys
    The size of physical memory available, in bytes.
dwTotalPageFile
    The size of the committed memory limit, in bytes.
dwAvailPageFile
    The size of available memory to commit, in bytes.
dwTotalVirtual
    The total size of the user mode portion of the virtual address space of the calling process, in bytes.
dwAvailVirtual
    The size of unreserved and uncommitted memory in the user mode portion of the virtual address space of the calling process, in bytes.

All these types are 32bit long, so the structure is 8*4=32 bytes long.
*/

VarSetCapacity(memoryStatusBuffer, 32, 0)


/*
void GlobalMemoryStatus(
  LPMEMORYSTATUS lpBuffer
);
We have a pointer to a structure (or buffer). It is an integer, we give it the address of our variable.
In a DllCall, past the first parameter, we alternate types and expressions, so quotes around the third param!
*/

DllCall("GlobalMemoryStatus", "UInt", &memoryStatusBuffer)


/*
Now, we need to retreive the values in the structure.
I like to use the simple following function, but you can use the ExtractInteger described in the DllCall manual page.
*/

GetNextUInt(ByRef @struct, _bReset=false)
{
   local addr
   static $offset

   If (_bReset)
   {
      $offset := 0
   }
   addr := &@struct + $offset
   $offset += 4

   Return *addr + (*(addr + 1) << 8) +  (*(addr + 2) << 16) + (*(addr + 3) << 24)
}

skip := GetNextUInt(memoryStatusBuffer)
memoryLoad := GetNextUInt(memoryStatusBuffer)
totalPhys := GetNextUInt(memoryStatusBuffer)
AvailPhys := GetNextUInt(memoryStatusBuffer)
; etc.
MsgBox,
(
Memory load: %memoryLoad%`%
Total size of physical memory: %totalPhys% bytes
Size of physical memory available: %AvailPhys% bytes
)

if not DllCall("Shell32\SHGetFileInfoA", "str", FileName, "uint", 0, "str", sfi, "uint", sfi_size, "uint", 0x101)  ; 0x101 is SHGFI_ICON+SHGFI_SMALLICON.