Проверка на существования файла

FileExists()

#include <GUIConstantsEx.au3>
$Flag = FileExists("C:\111.txt")
$Form1 = GUICreate("Проверка", 240, 120, -1, -1)
$Button1 = GUICtrlCreateButton("Есть", 16, 48, 80, 30)
$Button2 = GUICtrlCreateButton("Нету", 144, 48, 80, 30)
GUISetState(@SW_SHOW)

If $Flag Then
   GUICtrlSetState($Button2, $GUI_DISABLE)
Else
   GUICtrlSetState($Button1, $GUI_DISABLE)
EndIf

While 1
	$nMsg = GUIGetMsg()
	Switch $nMsg
		Case $GUI_EVENT_CLOSE
			Exit			
		 Case $Button1			
			MsgBox(64, "Инфо", "Eсть")
		 Case $Button2
			MsgBox(16, "Инфо", "Нету")
	EndSwitch
WEnd

#include <GUIConstantsEx.au3>

Dim $aButton[2] = ['Есть', 'Нет']
$sFile = @ScriptDir & '\test.txt'

$hGui = GUICreate('Проверка', 190, 110)
For $i = 0 To 1
	$aButton[$i] = GUICtrlCreateButton($aButton[$i], 10 + $i * 90, 40, 80, 30)
Next
GUICtrlSetState($aButton[FileExists($sFile)], $GUI_DISABLE)
GUISetState()

While 1
	Switch GUIGetMsg()
		Case $GUI_EVENT_CLOSE
			Exit
		Case $aButton[0]
			MsgBox(64, 'Инфо', 'Eсть', 0, $hGui)
		Case $aButton[1]
			MsgBox(16, 'Инфо', 'Нет', 0, $hGui)
	EndSwitch
WEnd