If you have Windows 98 you are running a machine thaqt is at least three or four years old and probably slow by current standards.
Not to mention that W98 isn't very good at multitasking, which means that background processes like virus scanners bog down the machine more than they would with XP.
I use Norton 2005 on one of my home machines with no trouble. I chose, at installation, not to install the Norton firewall. I have never liked that. My main reason for continuing to use Norton is that it is cheaper to pay the anual fee than to switch.
I use AVG on another home machine. It does not receive email, so I am not as concerned about it.
Athe work we use MacAfee, Norton and Trend on various machines. They all seem to work fine. The Exchange email server uses GFI, which filters viruses and spam. It is close to 100% effective against spam, but it is expensive and only runs on servers. It has also blocked new virus variants before they were reported in the media.
Rather than fight this any longer and wasting another entire day... we're going shopping for a new machine!!! The old Win98 rig just can't cut the mustard anymore because I've already learned you can't up grade the OS in these Compaq machines without up-grading the innards and Compaq's innards are too proprietary to easily replace!
Thanks for confirming the obvious. One just gets entirely too comfortable and attached to a machine and just hates to let go. I've noticed this weakness gets worse as I get older. (grin)
I've uninstalled Norton and taken the machine off line and am typing this reply on Mrs. Wasps newer Emachine!!!