whenever I switch on my computer, why does window security center shows that my computer is at risk ?

My windowdefender is turned off and security center does not recognises anti virus installled. Is my computer hacked ? Is my computer is at risk? I have installed mcafee virus scan. Is it enough or a new upgrade is needed? Why does it happen ? Please suggest some solution.


How to switch back to Avg anti virus from Avg Internet Security free trial ?

Ok so i had got avg anti virus and i downloaded the free one month trial of Avg Internet Security. Now the trial is ended so how do i switch back ?


LAN Switch Security: What Hackers Know About Your Switches

Product Description LAN Switch Security: What Hackers Know About Your Switches A practical guide to hardening Layer 2 devices and stopping campus network attacks Eric Vyncke Christopher Paggen, CCIE® No. 2659 Contrary to popular belief, Ethernet switches are not inherently secure. Security vulnerabilities in Ethernet switches are multiple: from the switch implementation, to control plane [...]