Microsoft Security Essentials won't block content of websites and won't interfere with them.

If you visit a website contains a virus , then Microsoft Security Essentials will display a notification that a virus been detected and you could click to see more details.

If a website is being blocked by a malware, it is usually by the browser for example Internet Explorer SmartScreen filter will block malicious websites.

Would you mind post back screenshot of this warning?

It could be a fake warning.

As requested, "Would you mind post back screenshot of this warning?"

Is Adobe Flash Player v15.0.0.189 (or higher) installed? TEST HERE USING INTERNET EXPLORER ONLY! => http://www.adobe.com/software/flash/about/

Is it the same computer as in this previous thread of yours? => http://answers.microsoft.com/en-us/protect/forum/mse-protect_scanning/additional-cleaning-required-and-must-run-windows/fe1d0f40-929b-4f4a-927c-c3d39a760af3

Java is NOT installed on this computer

I have version 15,0,0,189 installed of Adobe on this computer

It is NOT the same computer in the previous thread you posted

The latest version of Adobe Flash Player is 15.0.0.223.

http://www.adobe.com/ca/products/flashplayer/distribution3.html 

1. Can you successfully upgrade to Flash Player v15.0.0.223 (or higher) by opening Internet Explorer ONLY to this page? => http://www.adobe.com/go/getflash

• BEWARE any pre-checked options to "drive-by" install unwanted, third-party software (e.g., Google Toolbar; Google Chrome)!

2. Is KB3003057, KB3006226, KB3010788, KB2992611, KB2993958, KB3005607, KB2978120, KB3003743 and/or KB3002885 listed in Installed Updates (not Update History) now? [1]

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[1] cf. https://technet.microsoft.com/library/security/ms14-nov