http://www.alexa.com/prod_serv/msie.html
The "related links" feature, built in to MSIE 5 and above, uses this. Apparently, it sends back info to thier master server to determine which links go with what, IE, "people who surf here frequently surf here", like amazon.com's "people who bought this also bought that" thing. Possibly other things too. Rather icky that it's built in to Windows. It's also included in Netscape too:
http://www.alexa.com/prod_serv/netscape.html
Here's thier privacy policy:
http://www.alexa.com/company/privacy.html
(Note: Ugh.)
Also, check out these FAQ notes:
http://www.alexa.com/exec/faqsidos/h....html?index=12
...and...
http://www.alexa.com/exec/faqsidos/h....html?index=58
The second one seems to indicate that only the full version (which is a browser toolbar add-on) is actual spyware, because if you turn it off, it ain't spying any more. Dunno for sure though. It might be that adaware is detecting the nonspyware version in MSIE6 for some reason. But, again, who can tell?