Upgrade or Replace?
Your current PC is probably just the way you like it. You have all your music, all your photos, your favorites, your email just exactly where you want it...or at least you know where to get to it.
If your PC is moving slow, you can get it cleaned up for $100-$200. Chances are that it will be running as fast as when you got it. Kick in another $75 for another Gigabyte of memory and chances are you will be happy.
On the other hand, if your PC is 3 or more years older, you really should look at upgrading. Today's PC's are leaps and bounds ahead of your 3 year old clunker. You can pick up a dual or quad core processor, twice the hard drive capacity and memory. The down side is you will probably have to re-learn everything you know about Windows. Now that Vista is out and XP has been dropped you will have a learning curve. Not to mention the fact that you will have to transfer your data.
It's a tough choice. Too bad you can't get some kind of tax breaks for upgrading to newer, more efficient technology.
If you are strapped for cash, spend a little on your current PC and hold out until the economy improves. If you can afford a new PC, go ahead and bite the bullet. Who knows, you may be Vista's biggest fan.