Recently recieved this error message during a session of online gaming. I'm running Windows XP on 1.333Ghz ATX processor

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System Shutdown
This system is shutting down. Please save all work in progress and log off. Any unsaved changes will be lost. This shutdown was initiated but NT AUTHORITY\SYSTEM

Time to Shutdown : 00:01:00 (always allows just one minute)

Windows must now restart because the Remote Procedure Call (RPC) terminated unexpectedly.
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And it will count down to 0:00, restart and then bring up the same error message again. Is this a malicious hacker? A virus of some sort? any help at all would be appreciated