Upto what extent does these anti-virus, anti-spyware etc. slows down your pc?

what is the optimum ram required to install these anti-things so that it would not effect your pc's resources perfomance drastically?

Upto what extent does these anti-virus, anti-spyware etc. slows down your pc?best antivirus software

Those softwares can run with memory as low as 64mb since you never specified the speed of processor and the operating system you are running.

I am going to assume that you are using at least a P4 2GHz processor running on Windows XP Pro. If this is the case, you will need at least 128mb of memory (that's the minimum required for running XP with full capabilities).

As long as you are not using Norton, you are good. If you are planning on using Norton then I suggest you get at least 512mb of RAM. Norton is too resource hungry.

Upto what extent does these anti-virus, anti-spyware etc. slows down your pc?firewall

hi

It all depends on what Anti-virus prog u use

Avg is the best antivirus prog one can use efficiently without slowing down P.C speed

form optimal performance i would say any P.C especially if u browse a lot u atleast need a min of 1GB Ram
It is preferable to have a minimum of 1GB installed.There are many different types of viruses and it is best to carry out a minimum of 3 anti-virus and anti-spyware scans a week. Depending on the type of virus that has infected your computer depends on the amount of damage caused. To give you a better understanding go to www.badguys.org and on the Left side of the page click onto Papers
Based in my experience, the anti-things not use your ram much. But the optimum ram required is 1GB and the minimum is 512MB
Anti-Virus softwares depends of how much RAM they cost. It depends on their version and compatibility on your computer.

PC-cillin can run with only 256MB of RAM compared to Windows Live OneCare that costs 430MB of RAM. Anti-viruses like Norton, Trend Micro, Bitdefender, Kaspersky and Apple Care doesn't affects your computers performance. Don't try to run both programs that uses high amount of RAM. Clean your hard-drives and defragment once a year and perform a full clean scan every month.