which is the best anti- virus program for PCs

Yes! Norton does use a lot of memory, thus making your system slow down. If you would mind, why not give a try Avira AntiVir Personal Classic Edition. Since using this one, I have never had any problems at all with regards to the system performance of my machine. It updates on a regular basis and can be scheduled at your most convenient time. It is very light on resources and does not use a lot of memory. It does not slow down your computer. It detects and deletes rootkits, viruses, worms, etc. I am so satisfied with its performance. Hope this would help. Have a nice day!

we had norton and our computer was doing that too so we changed to windows live one care and it is great once our free trial is over we will deffinately be buying it

I've used Norton and McAfee. I liked McFee better, but Norton was cheaper. At the moment, I don't have true virus protection. I just use SpyBot.

Your RAM needs be upgraded. Not only anti-virus software, but also firewall is needed at the same time. For anti-virus software, Kaspersky is the best. As for firewall, there are many kinds of products in the market, you can choose one.

i think kaspersky will be best 4 ur pc

You should try the best one McAfee with Spam killer.... Currently i am using McAfee antivirus with Spamkiller since i have installed windowsXp on my system so when i had windows installation the seller adviced me to chose McAfee ....the reason he gave me that it will not effect much on your pc speed as compare to norton and others ..so i said okey ....... so i am pretty much satisfied with Mcafee antivirus now ...........