Why not use Windows Defender on Windows 8
which integrates a more robust version of Windows Defender (and uses that name) for its anti-virus and anti-malware protection? Although it uses the same name, it is not the same as Defender in previous operating systems. Windows 8 Defender provides the same level of protection against malware as Microsoft Security Essentials (MSE) and uses the same virus definition updates.
* Windows Defender on Windows 8 - Introduction and FAQs
* Windows 8: new and improved security features
* Windows 8 Security: Defender Antivirus
* Windows Defender and Windows SmartScreen
There are several labs which test the effectiveness of major anti-virus programs to include AV-Comparatives.org, Virus Bulletin Comparative Tests, AV-Test.org, NSS Labs Consumer Anti-Malware Products Group Test Report, etc.
TopTen Reviews is not one of them.
BTW, these kinds of comparative testing results will vary
depending on a variety of factors to include but not limited to who conducted the testing, what they were testing for (type of threats, attack vectors, exploits), what versions of anti-virus software was tested, what type of scanning engine was used, and the ability to clean or repair. There are no universally predefined set of standards
or criteria for testing which means each test will yield different results. As such, you need to look for detailed information about how the tests were conducted, the procedures used, and data results. Read Anti-virus Testing Websites: An overview of testing sites