Use www.panicware.com for PopUp-Stopper, www.lavasoft.com for Ad-Aware, www.zonealarm.com for ZoneAlarm and http://www.download.com/3000-8022-10122137.html for SpyBot S&D.
Anyone attempting to get Ad-Aware should be careful: there is a product called Ada-ware which is NOT what you want.
The Ad-Aware product mentioned and endorsed on this thread is from LAVASOFT.