[madmasles]

Serg2010,
Попробуйте так.

Код:

;#include <Array.au3>
#include <File.au3>

Global $sDir = @ScriptDir & '\BackUp\', $sMask = '*.au3', $iCount

If Not StringInStr(FileGetAttrib($sDir), 'd') Then Exit -33

$aFiles = _FileListToArray($sDir, $sMask, 1)
If @error Then Exit -55
;_ArrayDisplay($aFiles)
For $i = 1 To $aFiles[0]
    $sDate = ''
    If StringRegExp($aFiles[$i], '^\d{4}_\d{2}_\d{2}_\d{2}_\d{2}_\d{2}_') Then ContinueLoop ;если уже переименованы
    $aTime = FileGetTime($sDir & $aFiles[$i], 1)
    If @error Then ContinueLoop
    For $j = 0 To UBound($aTime) - 1
        $sDate &= $aTime[$j] & '_'
    Next
    If FileMove($sDir & $aFiles[$i], $sDir & $sDate & $aFiles[$i], 1) Then $iCount += 1
Next
MsgBox(64, 'Info', StringFormat('All files: %d\nRename files: %d', $aFiles[0], $iCount))