If you get something named Antivirus 7, please don’t install it. Although the name looks very similar to Windows 7 but it is not legitimate. Antivirus 7 is a fake/rogue antivirus program that does not protect you from viruses. Actually this rogue antivirus is installed through the use of trojans and often bundled with other malicious softwares.
The alarming thing is that most of the antivirus softwares are unable to detect Antivirus 7. See the report from VirusTotal where only Symantec Antivirus was able to detect Antivirus 7 as Suspicious.Insight.
Here is what Jovita says about Antivirus 7: