All computers are only able to process just so much stuff before they start to slow down. There are a couple of different things that regulate how quickly you'd be able to process all that stuff, but the first place to check is your memory.
If you right click on the "my computer" icon on your desktop and choose "properties" you'll see how much memory your computer has listed on the bottom. It should look something like 480MB RAM (that actually means my computer has 512 MB, how confusing is that?).
You can also look at your processing speed, but that's a whole lot harder to change.
If you have less than 512MB (it says anything lower than 480MB when you go to properties) than you might want to look at upgrading your RAM, which isn't terribly expensive. Less than $50, usually.
If peoples' profiles with all the stuff on it is the only place you have trouble, I wouldn't bother.
at 9:50 AM on Nov. 11, 2008