If you've happened to notice that you've gotten hit by spyware, the first step is cleaning the mess... If you haven't noticed it yet, there may be something hidden on your system that you don't know of yet...

There are a lot of titles that one can find by searching, but these are ones we've tested:
SpyBot Search and Destroy
Spybot – Search & Destroy is a spyware and adware removal computer program compatible with Microsoft Windows 95 and later. It scans the computer hard disk and/or RAM for malicious software. Spybot-S&D was written by the German software engineer Patrick Michael Kolla, and is distributed by Kolla's Irish company Safer-Networking Limited. Development began in 2000 when Kolla, still a student, wrote a small program to deal with the Aureate/Radiate and Conducent TimeSink programs, two of the earliest examples of adware.

Windows Defender
Windows Defender is software that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software by detecting and removing known spyware from your computer. It delivers a robust suite of security features that keep you safe for the supported lifetime of your Windows 10 device.

Malwarebytes
Malwarebytes is an anti-malware software for Microsoft Windows, macOS, Android, and iOS that finds and removes malware. Made by Malwarebytes Corporation, it was first released in January 2006. It is available in a free version, which scans for and removes malware when started manually, and a paid version, which additionally provides scheduled scans, real-time protection and a flash-memory scanner.

SUPERAntiSpyware
SUPERAntiSpyware is a software application which can detect and remove spyware, adware, trojan horses, rogue security software, computer worms, rootkits, parasites and other potentially harmful software applications. Although it can detect various types of malware, SUPERAntiSpyware is not designed to replace antivirus software.

SpywareBlaster
SpywareBlaster is an antispyware and antiadware program for Microsoft Windows designed to block the installation of ActiveX malware.