Spyware can be embedded in a program that you downloaded yourself (such as RealPlayer) or program you gave permission to download & install, or just a cookie that activates when you hit a certain website. All of these come through the http internet port 80, so a firewall doesn't block them (unless you blocked access to the internet.
Computers have hundreds of ports that can be used to communicate various things & that's what a firewall is designed to manage & close. For example, your e-mail program most likely uses the standard pop3 & smpt ports of 25 & 110.
If you configure your firewall to close those ports (in this example), then you would not be able to send/receive e-mail with that program.
Goodnesswins, Ad Aware runs fine on Win98 & all versions of Windows.
FlyVet, you don't have to delete all of your cookies to get rid of spyware, but you should periodically examine them & delete all except those you need (like FreeRepublic).
A good web site to check out for info on spyware & internet privacy issues is:
http://www.grc.com/
FReegards,
RebelTex
Thanks for your rational response. Like I said, I run AdAware daily and almost always find spyware on my system. But I still wonder why it's legal. I don't have a problem with cookies that provide a "memory" to such sites as TV listings or e-mail, since it's a convenience not having to input info every time you visit the site. Spyware, monitoring your surfing activities, uninvited, I don't understand that. Shouldn't be legal. I think it was the Sun Microsystems CEO that was quoted a few years ago, "There is no privacy, get over it."