Macbook Aluminium 13" Randomly Freezes

Hello, people!

I have a Macbook Aluminium 13" (Core 2 Duo 2GHz, 2GB RAM and 160GB HDD) that randomly freezes in several different stuations.

Abou two months ago, it was being used by my mother and it suddenly stopped working. She was using Safari and the coloured-spinning circle went up and didn't stopped for a long time. Meanwhile, I tried to open/close windows, open "About this Mac" window and several other things. No success.

After a while, I forced it to turn of by holding down the power button and tried to reboot it to see if it was a isolated event or if it would happen again. Turns out that the it was not a isolated event and the Mac stopped working again, but right off the start, it would't even launch Safari or any other program...

As I had Bootcamp on that laptop, we started using it on our Windows partition and everything was running really smooth (on Windows). No freezes, crashes or even BSOD (which i tought was really inpressive).

One or two weeks later, when I had time, I formatted the Macintosh partition and tried to install Mac OSX Snow Leopard (the laptop default OS is Leopard, but I had bought a copy of Snow Leopard) to see if it would be different.

The system installed, normally, rebooted, played the Apple "welcome" video and led me to the first configs (those where you choose an Wi-Fi connection, Apple ID, username and profile picture) but it turned out that the system would't even be able to end these configuration steps.

Sometimes it froze at the Wi-Fi config, but mostly it froze at the image changing option with the same symptons: coloured spinning-circle and no response of any other command. If tryed to foce-reboot, the "welcome" video would be played once more and I had to go through everything again.

I left the laptop aside for about two months after this, and today I decided to make it work, but not. Formatted the whole HDD (excluded the Bootcamp partition including) and chose the Zero Config option at the formatting options. Installed the system and made through the config steps to end up with the system freezing at the image change. Everything same as before, but now, after force-rebooting the system booted, launched normally (almost) and left me on my desktop ( ! ). After trying to launch System Preferences the laptop froze and I could do nothing again.

Force-rebooted again and me it to "About this Mac" window AND was able to click "More Info...". The new window poped out and I could read my laptop specs.

As I'm wrinting down this post, I tryed to see some other options of that laptop, just to see it freezing again but this time, things got harder.

No coloured spinning-cicle and mouse won't move (every other time it moved). Anyway, I'm able to press the dashboard key (on the keyboard), power key and a few other , and they work (every other time they worked too).

So now I'm with this Mac that can't see to be able to work without freezing.

I've already tryed to reset PRAM, SafeBoot, Disk Repair, System Repair, Repair Repair and any other things that I could imagine to do... The only thing that I haven't tryed yet was changing the hardware. maybe the RAM is gone. IDK.

Any ideas?

Cheers!