That's two issues. Both have very little to do with Windows 2000/NT but a favorite discussion of mine.

1. Not all tools find all pests. After a pass with Adaware and Spybot, unless I know the name of the pest I proceed to HIJACKTHIS and research what items I don't recognise with GOOGLE.COM.

2. You write "is there anything I can do to prevent this pop-ups from coming back?"

That's a good question. I want you to consider that most of these popups are installed by exploiting Internet Explorer (IE), Outlook (all versions) and sometimes by getting the person to open an attachment.

At the office we hid IE away and Firefox is front and center. Since it was costing too much IT time for spyware removal runs, the hammer had to come down since Microsoft has been slow to tackle this issue.

I offer NO CURE for IE. This may upset some, but for those, they will just have to look elsewhere for now.

Best of luck,