Hi colleeh,
Yes, your computer is fairly old, but it may be serviceable for what you need it to do.
What Operating System are you using (Windows 98, XP, Vista, 7)?
What programs do you use the computer for(web surfing, word processing, etc.)?
If you're not comfortable upgrading your system we could help you find something if you provide a little bit of information about your budget and what you typically use your computer for.