A properly hardened workstation with well trained users NEVER needs antivirus
Yes, it does.
Antivirus software will notice about the virus,malware,spyware etc
Simply download the installer for the antivirus, then run it. With some antivirus software you don't even need to install it!
anti virus
Yes, a computer must be turned on to run an antivirus scan. All programs residing in an operating system (and the operating system itself) will work and function if and only if the computer is booted. However, you can still run antivirus while the computer is idle. Some antivirus scanners will still work if the computer runs into sleep mode. Software needs hardware to be able to work. So, you need to boot up the computer to start any programs (including antivirus scan).
You can install anything on a computer. However if you want your antivirus system to work you need to have one working or none will.
You need the same hardware, firewalls, and antivirus software to protect one computer as you need to protect 25.
By using Antivirus
Install it from the disc that came when you bought Norton AntiVirus. If it came bundled with the computer than you may need to download it again from the Norton website.
You need antivirus to protect your computer from being destroyed by malicious software. Some great free programs that do what their ment to do are AVG and AVAST. Try them. Thanks a lot really good answer :) Anti virus software stops hackers software damaging or destroying your computer.
you do not need to buy things like that until you completely know about it!
antivirus