John is correct in his assessment. One thing to consider, is the computer is now 10+ years old and cannot run current versions of Mac OS and has very limited value. Investing about $200 in a machine with little value does not make a lot of sense.
Have you considered replacing the computer with a new machine? If you are there are many options available to you for various Mac models and also how much you pay for them. To reduce costs consider buying from Apple's refurbished program (www.apple.com navigate to the bottom of the page and click the Refurb section) . There is zero downside to an Apple refurb as they are identical to new, have the same warranty as new, are eligible for AppleCare and can save hundreds of dollars.
Just something to consider.