Why my system stop working?

many possible reasons this would suddenly start happening, but without more background information (what have/are you doing right before the hang) it's impossible to accurately diagnose.

Some possible reasons could be:

• overheating that's an old machine and could be full of dust, or the thermal paste dry and inefficient, senors or fans starting to fail.
• A failing HD
• Problematic New RAM or other hardware.
• New software attempting to "phone home" in the background to check for updates or registration and hogging resources until it times out or gives up.
• A network issue, similar to above but possibly email or video streaming application, Some applications are notorious for this.
• Corrupt preferences or permissions

Provide more details to receive more assistance, OR search "Hang" or "freeze" and look at Answers for other solutions.

Remember to return and mark accepted the answer that best solves your problem.

Good luck,

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