There is no one spyware program that will catch everything.
They all look for different things.
That's why it's a good idea to have several, as anyone here will tell you.
I don't have any experience with Windows Defender
, so I can't comment on it, but Spybot
are very good programs.
Here's a list of the ones I use:
(They're all free.)a² freeewido security suiteAd-AwareSpybot S&D
These 2, will help prevent spyware/malware from being installed in the first place:SpywareblasterSpywareGuard