You can run below script in IIS for cleaning the logs

 

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Dim fso, folder, file, filecollection, dir, days_in, days_dif, filesplit

'Dim WshShell
'Set WshShell = WScript.CreateObject("WScript.Shell")
'WScript.Echo WshShell.CurrentDirectory

If ((Wscript.Arguments.Count < 3) or (Wscript.Arguments.Count > 3)) then
    Wscript.echo "Script requires 3 parameters"
    Wscript.echo "cscript log_clean (directory) (days) (extension)"
    Wscript.echo "cscript log_clean c:\ 30 log"
    Wscript.echo "(directory) is folder to delete logs out of"
    Wscript.echo "(days) sets the age for a file delete, if file older then (days), it is deleted"
    Wscript.echo "(extension) sets which files the tool will look at)"
    Wscript.Quit 3
    end if
   

dir = Wscript.Arguments.Item(0)
days_in = Wscript.Arguments.Item(1)
ext = Wscript.Arguments.Item(2)
    

set fso = CreateObject("Scripting.FileSystemObject")
set folder = fso.GetFolder(dir)
set filecollection = folder.files

For Each file in filecollection
       
        filesplit = Split(file.name, ".")
       
        If (Ucase(filesplit(UBound(filesplit))) = Ucase(ext)) then
       

        days_dif = DateDiff("d", file.DateLastModified, date)       

            if ((cint(days_dif)) > (cint(days_in))) then
       
                wscript.echo file.name&" is "&DateDiff("d", file.DateLastModified, date)&" days old"
                wscript.echo "Will delete "&file.name
                file.Delete[(force)]
            else
       
                wscript.echo file.name&" is "&DateDiff("d", file.DateLastModified, date)&" days old"
                wscript.echo "Will keep "&file.name
       
            end if
        end if

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