Let's see...
I run the full Norton suite and it doesn't cause me any trouble. Most free antivirus programmes can't catch a cold without written instructions, be warned.
If you are running MSOffice and have the Office Shortcut Bar up - get rid of it. It takes 18% of whatever you have. (No, I don't know why either...)
I highly recomment Lavasoft Ad-Aware to kill off spyware. Works well, is free, and is something free that I'd be willing to pay for (high praise!)
Concur with clearing out the system tray (near the clock) on the taskbar. Hit ctrl-alt-del and go thru the list - you'd be surprised what's running! If you want, type out the list and email it to me, and I'll give you an idea what's doing what.
If you have Norton Speed Disk (in SystemWorks or Utilities) try this -
A) Right click "My Computer" - "Properties" - "Performance" (I think on the last one.) You should be able to find a setting to alter virtual memory. Set to "zero" or disable it, and reboot.
B) Defrag with Norton Speed Disk. This will take a while, owing to no swap file.
C) Reboot after defrag, and go to your VM settings as above. Rest Virtual Memory - I think I usually allocated 5x physical RAM for VM, drive space permitting.
What this will do is a thorough defrag of the hard drive, and reallocate the swap file as a single "zone" on the drive. This will usually make a significant difference in system performance, and should be done about twice a year. Do your normal defrag about once a month.
If you want more after that, hit me backchannel and we'll talk.
5-90