spysweeper (free) is also a good one..
but be carefull alot of spyware removal programs can contain spyware
like someone pointed out above using different browser other than IE can help
IE is most widely used and hated (therefore most targeted).
try: netscape,mozilla, opera... also more secure than IE for same reason
you'll also want nortons antivirus always kept up to date. or whatever antivirus ur using
and finanly you can never fail with a good firewall
zone alarm at zonelabs.com
running a spy sweeper program, keeping your anti virus up to date and running a firewall should make you a happier man