In case you haven't done anything drastic yet may I suggest you try,
Check the hard drive condition with "Speedfan". It is a free download and will check out the hard drive along with giving you the temperatures of the hard drive and processors, one or two or what ever.
It is free to download and serves me well, since laptops get warm easily. Here is a link to version 4.46
As for slowing down, Norton is famous for slowing things down because it works so hard and constantly.
I might suggest Free "AVG" or MSE (Microsoft Security Essentials). Both are free to download or you can pay for a Complete version of AVG. I always read good reports on both.
If you think you need to clean out all the cobwebs and left over little stuff you can try "Ccleaner", also free and it gets rid of those pesky left overs at the end of the day. I use it daily.
If after all these cleaning thinks your laptop is still acting up, then it is indeed time to say RIP.
Hope this helps.
Link to Ccleaner http://www.piriform.com/ccleaner
PS, If you are going to remove Norton you might try free "Revouninstaller". Shows all your installed programs and removes little tiny registry left overs.Works wonders.
Link to basic AVG Free http://www.avg.com/us-en/free-antivirus-download
Edited by waterslaw, 12 May 2012 - 10:22 AM.