Don't have a pop up blocker for you, but I have a link for a fire wall that I think will do that as well.
Here's the link for the best personal firewall I've ever used, called "Tiny
Personal Firewall".
It really is tiny...will almost fit on a standard floppy. Find it at:
http://www.pcworld.com/downloads/file_description/0,fid,8051,00.asp
Also, the PC World link for a good anti-spy-ware detector program from
Ad-aware.
http://www.pcworld.com/downloads/file_description/0,fid,7423,00.asp
Both are freeware
Here is another link to a good SPAM filter it is very effective has has gotten rave reviews.
http://www.giantcompany.com