I face something tough about Mac.It is five years old and works slower and slower,but I can't deal with it.One of my best friend on line told me to buy a new mac-os-software[, but it costs a little;I want to know whether it is worth to buy it?
Is there anybody who knows well about MAC-os-software can give me some suggestion?Thank you very much!

For starters, you posted this in the wrong forum. I have a powerbook I bought in '05 and I still run OS/X perfectly fine on it. Sounds like you might want to just wipe the drive and reinstall the OS. I'm guessing you probably have Panther on it now. I can't suggest buying new "mac os software" without knowing what software you're talking about.

In short, reinstall your OS.

Thank you very much for your advice!I will try to do as your guide.But I'm sorry ,and I think maybe I didn't say clearly.
I use a five-year-old Apple iMac G4, with 256 MB of RAM and OS X 10.3, now it works slowly. Especially when I connect my ipod touch 3(32g) with it. The itunes doesn't open(I've chosen when connect ipod, itunes runs automatically). I wanna know is there something wrong with the hardware, or software?

iTunes has become a bit bloated, and running with only 256MB of ram will definitely slow you down. I'm also assuming your iMac is probably only 800MHz or so.

I doubt anything is wrong with the hardware, other than being rather outdated.

Either your iMac needs a clean install to speed things up, or it's just too slow for today's standards of operation.