bmurty, you are using Ad-Aware SE Personal as Mitch11 suggested? It is an improvement on Ad-Aware 6.
Important
You absolutely
must turn off System Restore prior to running
any antispyware, adware, malware, AntiVirus scan, etcetera, otherwise you run a strong possibility of being reinfected. Turn it on again after you have completed the scans, if you wish to.
Microsoft Knowledge Base Article - 310405
How to turn on and turn off System Restore in Windows XP
Also dl, install, immediately update and run the following free app in addition to Ad-Aware SE Personal.
Spybot-S&D 1.3
Spybot-S&D 1.3 Tutorial
Let us know how you get on.