There is no one size fits all when it comes to antivirus and security programs. What works well for some won't work for others. Try another antivirus, there really isn't anything (at least that I'm aware of) that you can do to tweak Norton so it doesn't slow the computer down.
Now that you've uninstalled Norton, use the removal tool from Symantec to get rid of the traces Norton is notorious for leaving behind. This thread http://www.bleepingcomputer.com/forums/t/34671/how-to-remove-your-norton-products/
will provide the info for and the link to the removal tool.
Also, if you haven't installed another antivirus, this thread will give you some programs that you can choose from http://www.bleepingcomputer.com/forums/t/405/antivirus-antimalware-and-antispyware-resources/
Edited by Queen-Evie, 28 March 2007 - 04:54 PM.