ITS GOOD KEEP TWO ANTIVIRUS IN SYSTEM TO PROTECT !!!
According to the test and research conducted by me. I have found that its not recommend to keep two antivirus in the system because it (technically) uses lot of memory and system cycle to process the file (that we call it as scanning) .Not only that start up process will also become slow due to number of services started by the antivirus programs.so its better to use one antivirus in the system.
Not only using antivirus will protect the system.but due care most be taken from your side as well to maintain the system with not installing unwanted applications and software.
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