I generally like to keep the current months web logs around for convenience, and I’m not the kind of IT guy who likes to delete log files.. no waste disk space.. so I use this script to accomplish the goal.  Yes, this could be better written, but for now, it serves my goals of archiving my weblogs to individual .zip files (I hate super huge zip files, as it can be tedious to extract a single file).

I set the variables at the top, then configure this as a scheduled task to run monthly.  Voila, all log files from previous months get automatically archived to individual zip files for me.  Lots of disk space savings (Especially on large log files)

Option Explicit
    Const ForWriting = 2
'on error resume next
Dim objFSO, objTxt, intMonth, intYear, filenam, objNewZipFolder, THISintMonth
Dim objApp, myFolder, objItem, objItem2, myZipFile, found, logprefix

'************************** CHANGE THESE VARIABLES ********************************
logprefix = "ex"
myFolder = "D:\inetpub\website\W3SVC1002222222"

'**********************************************************************************
' Then run this script from a cscript dos window (cscript scriptname.vbs) and Voila.. Zip's

intMonth = Month(Date)
THISintMonth = Month(Date)
intYear = Year(Date)

If intMonth = 1 Then
    intMonth = 12
    intYear = intYear - 1
Else
    intMonth = intMonth - 1
End If

If intMonth < 10 Then
    intMonth = "0" & intMonth
End If

if THISintMonth < 10 Then
    THISintMonth = "0" & THISintMonth
end if

intYear = right(intYear,2)

    ' Create a Shell object
    Set objApp = CreateObject( "Shell.Application" )
    For Each objItem in objApp.NameSpace( myFolder ).Items
      if instr(objItem.Name,"ex" & intYear) and instr(objItem.Name,".log") and not instr(objItem.Name,"ex" & intYear & THISintMonth) then
        filenam = objItem.name
        filenam = replace(filenam,".log","")
        'wscript.echo filenam
            myZipFile = myFolder & "\" & filenam & ".zip"
        ' Create an empty ZIP file
        Set objFSO = CreateObject( "Scripting.FileSystemObject" )
        Set objTxt = objFSO.OpenTextFile( myZipFile, ForWriting, True )
        objTxt.Write "PK" & Chr(5) & Chr(6) & String( 18, Chr(0) )
        objTxt.Close
         WScript.Sleep 100
        Set objTxt = Nothing
        Set objNewZipFolder = objApp.NameSpace( myZipFile )
        objNewZipFolder.copyHere objItem
        wscript.echo "Working on " & myFolder & "\" & filenam & ".zip"
        found=false
            do until found=true
            WScript.Sleep 10000
                if objFSO.FileExists(myFolder & "\" & filenam & ".zip") then
                WScript.Sleep 5000
                if objApp.NameSpace( myZipFile ).Items.Count > 0 then
                    found=true
                end if
                        else
                'wscript.echo "NOT FOUND YET"
            end if
        Loop
          wscript.echo "DELETING " & objItem.name & " NOW"
        on error resume next
        WScript.Sleep 10000
            objFSO.DeleteFile myFolder & "\" & objItem.name
        if err.number > 0 then
              wscript.echo "error DELETING - in use, trying " & objItem.name & " again in 30 seconds"
            WScript.Sleep 30000
                objFSO.DeleteFile myFolder & "\" & objItem.name
        end if
        on error goto 0
          end if
    Next

Note:  I TAKE VIRTUALLY NO CREDIT ON THIS SCRIPT.. I HACKED IT TOGETHER FROM NUMEROUS ONLINE SOURCES AND JUST DEBUGGED IT TO WORK WELL FOR ME (I added a few timer sleep functions to ensure the zip was completed before continuing, not the most optimized, but it works for me with log files < 1G/day..).  USE AT YOUR OWN RISK