Power Mac G5 tower login problem

Hello everyone,

I have a problem that I need some advice on for a diagnosis.

I have a Power Mac G5 tower dual 1.8 ghz/superdrive machine that I've had for about 6 years now. I am running OS 10.5. In the last few days, I've had a problem, that I'm not sure about.

After I get to the login screen and enter my password, the computer will freeze at the space screen. It will sit there for a few minutes (at least that's as long as I've given it), and then I will press the power button to power down and retry it. It has worked until today, when I tried it and it did the same thing a second time.

I'm not sure if this is a signal that my boot hard drive is having problems and may be going out or not. My wife and I have been looking at replacing the tower with a new macbook pro, and if the hard drive is going out on this, then it may be time to pull the trigger, but I'm just trying to figure out if the G5 problem is the hard drive failing, or maybe a software issue?