My Mac has not always been sluggish but now it is, unless I shut it down everyday. It is sporadic. I'm afraid it has something to do with my anti-virus updates but I know nothing about computers. Anyway, it is a PowerBook G4 version 10.3.9 with a processor 1GHz Power PC G4, Memory 564 MB DDR SDRAM.
First of all, I think it's important to say that you really don't need virus protection on your Mac, and if it's what holding things up, it'll be the first thing I ditch from a Mac.
So, here's the deal: Your Mac is slow because you have near the bare minimum memory necessary for your computer. Bringing it up to at least 1.5Gb (gigabytes) should help performance a fair bit. I encourage all modern Mac users: Install at least 2Gb (that's two gigabytes) of RAM, and you'll have a modern, happy Mac. And if you can afford it, and you're going to do anything serious with it, take that sucker to 3Gb.
I have, after much observation, found that having less than 1Gb of RAM (memory) can really slow a Mac down,
#1 - If you're still using OS X 10.2 Jaguar, you seriously need to upgrade to Tiger 10.4.
#2 - You actually shouldn't have to shut your Mac down unless you are going to be away from it for a while, or unless you have done a software installation or update that requires a restart.
#3 - There are a couple of basic troubleshooting techniques for a slow Mac, but the main one is to use the Activity Monitor, to be found in the Utilities folder inside Applications:
I'd like you to bear with me through the next couple of (brief) paragraphs. It's going to sound quite geeky, but it should help us examine your problem.
When you open Activity Monitor for the first time, you'll want to do two things: Change the "Show" drop-down menu to "All Processes", and click the "% CPU" label. This will show you which applications, or processes, are taxing your computer most.
And at the bottom of the window, you'll see a bar graph. If that graph is almost all black (and your computer is sluggish), then we're looking in the wrong place. If you have a lot of green or red in there (say, more than 20%), I'd like you to call or email me what processes are listed in the window as taking up the most of the resources.
(For kicks, here's a more complete article on using Activity Monitor.)
#4 - Now, here's another, and fairly important question: Do you use a lot of different fonts? If so, try closing them and see what happens. (If you're not sure what I'm talking about, then fonts are not the issue.)
#5 - Finally, there are a couple of maintenance tasks that one can perform. I can walk you through them over the phone. I'll mention that the tool I like to use is Onyx; the version of it for your Mac can be downloaded by clicking here.