Ad-Aware SE was discontinued some time ago. See here:
ATTENTION: Ad-Aware SE Personal users
SE has expired 31 Dec 2007, upgrade to v. Ad-Aware2007 nowhttp://www.lavasoftsupport.com/index.php?showtopic=16176Ad-Aware 2007 (and now new version 2008 released today) does not support either Windows98 or ME. So an upgrade to those new versions isn't possible on those operating systems.
While updated definitions are still being offered for manual updates, this doesn't mean that we intend this as a "extended support" measure for Win98 or ME using Ad-Aware SE. It is there only because of some commercial and paid license holders of SE who are still in upgrade status.
Check this page for alternative programs (Trusted Antispyware Programs at SpywareWarrior)
http://www.spywarewarrior.com/rogue_anti-s...htm#trustworthyIn that list, I'm aware of 2 free products listed that still support and will work on older systems such as Windows98 and Windows ME
SuperAntispyware and Spybot Search and Destroy (use the right links from the page listed).
For users with Windows 2000 and up operating systems, Ad-Aware 2008 is now the recommended upgrade for all Free, Plus and Pro users of Ad-Aware.