We cannot help you to write a script as you do not have enough experience, and it is a more complicated issue than you think it is.

Here is a script which will do the job:
Code:
Break ON
$gDiscard=SetOption("Explicit","ON")

Dim $sStartDir,$sRoutine

$sStartDir="C:\temp"
$sRoutine="udfDeleteZeroLengthFile($$sEntry)"

udfEnumDir($sStartDir,$sRoutine)

Function udfEnumDir($sDir,$sCall)
	Dim $sEntry,$sDiscard
	$sEntry=Dir($sDir)
	While Not @ERROR
		If Not($sEntry="." OR $sEntry="..")
			$sEntry=$sDir+"\"+$sEntry
			If GetFileAttr($sEntry) & 16 udfEnumDir($sEntry,$sCall) EndIf
			$sDiscard=Execute($sCall)
		EndIf
		$sEntry=Dir()
	Loop
EndFunction

Function udfDeleteZeroLengthFile($sPath)
	If Not (16 & GetFileAttr($sPath))
		If GetFileSize($sPath)=0
			If @ERROR=0
				"File "+$sPath+" is zero length - deleting..." ?
				Del $sPath
				If @ERROR "Error deleting file: "+@ERROR+", "+@SERROR ? EndIf
			EndIf
		EndIf
	EndIf
EndFunction


Change the variable "$sStartDir" to match the directory that you want to purge, and run the script to delete zero length files.

I strongly suggest that you backup the file store before you begin the delete.