Install, update and run a top-tier active antispyware program. There are many certified security programs to choose from and you will find links to some of them below. It is ultimately up to you to choose what you want to run, but I will also identify my favorite based on many years of personal use. But, never run more than one “active” security program of the same type, meaning only one antispyware, one antivirus and one firewall program. Running two programs of the same type can cause severe Windows stability problems. This limitation does not apply to “passive” security programs.
MalwareBytes Free detects and removes spyware.
Spybot Search & Destroy detects and removes spyware and provides passive protection for Internet Explorer.
SUPERAntiSpyware Free detects and removes spyware.