Basic VBScript
Code:
Set wshshell = wscript.CreateObject("WScript.Shell") ' starts the whole thing
do ' starts looping
wscript.sleep 150000 ' idles.time measured in ms. this is 150seconds
wshshell.sendkeys "a" ' sends a button which is usually goto left
wshshell.sendKeys "%{ESCAPE}" ' alt-tabs to the next window
wshshell.sendkeys "a" ' sends a button
' This code alt-tabs once, so if you are running more than 2 windows, copy the last two lines for 1 more window.
' OMGWTFOWNED 2012
loop ' loops the whole shit again
The code already works, so you can copy-paste it to a file, call it TheAwesomestBot.vbs and start it up