Restart problems

Recently, in the middle of using the computer, I get a message telling me to restart the computer, even when it is sitting on a stable surface. When the message appears I can only shut down using the power button. Booting up using the power button sometimes brings up the log in page and other times the screen remains dark and I hear a fan-like sound. After removing the battery briefly I can usually restart normally.
What is going on here?
This iBook is 6 years old and probably long past its due date but unemployment has me hoping it will last a little longer. The OS was recently upgraded to 10.5.8 and I have about 10 gigs of free space right now. Up until the last few days, the computer has been fairly trouble-free.

Might be time for a new Hard Drive.

10MB? You need to clear some space NOW or your entire hard drive could corrupt and you could lose everything.

Lack of hard drive space is your problem. To work anywhere near peak efficiency, a drive requires 15% or so free disk space. So a hard drive with say 100GB capacity, should only be used up to 85GB maximum.

I thought that was a typo had to go back and reread as I agee with others 10MB is
not enough thought the OP meant 10GB.

osxx said:

I thought that was a typo had to go back and reread as I agee with others 10MB is
not enough thought the OP meant 10GB.

Click to expand...

Yes, ten gigs it is, with a 60GB hard drive - temporary short between the headphones when typing entry.

osxx said:

Might be time for a new Hard Drive.

Click to expand...

Is there a way for me to determine this, or does it need to go into the shop?