Get rid of Norton and get the free editions of AVG and Zone Alarm. Norton is well known as a resource hogger. I used Norton for several years, and it was all ok until I bought Norton 2006.My Laptop immediately slowed down. I percevered for the whole of 2006, but did not renew my Norton subscription. Using AVG and Zone Alarm made an immediate difference to the speed of my Laptop, and I am really happy with their performance.
As for your wireless speed, I dont really know the answer. I had a similar problem about 6 months ago, and tried a new router, but it made no difference. In the end I went back to a wired connection.Recently I decided to try wireless again, and everything was fine this time, even though I am using the same router I tried 6 months ago.I have absolutely no idea why it is all ok now, and I am using the same Laptop and the same Broadband connection.