Software :: Mac Keeps Freezing Repeatedly - Need To Restore?

I bought an Ibook G3 two weeks ago. Its got mac 10.4.11 on it. Its processor is 600 mhz, and its memory is 192 mb sdram. It worked fine when I got it. Basically it keeps freezing repeatedly, and nothing unfreezes it. When I do command option, escape. it either does nothing, or the screen goes completely haywire. Then sometimes when I restart it, the screen is completely black, and I have to restart it over and over again until the screen comes up again. Sometimes when it is running the screen goes haywire (meaning all of the colors turn into lines) and then it goes away. I know the battery is weakening and is about to go, but all this happens with or without the battery. I also tried removing all power sources and holding the power button for 60 seconds but that didn't work either.

So I called the company that sold it to me, and they told me I need to restore it and buy a disc of that version of mac. They said I must have downloaded something that didn't agree with it. But could that really make the screen go black? I really need a second opinion before I go ordering anything. Bc if I do, by the time I get the disc it will probably be too late to return it if it doesnt work. I have tried to get anything that I have downloaded removed,and it is still freezing. Is there any way to get straight to everything I have downloaded and trash it all without having to order the disc? I mean I've only had it two weeks. Most of the things I downloaded were from the apple website.