Repeated Sudden death but no Blue Screen, Event log info copied.

Well, I have started in the last week or so to find that my Windows 7 64bit Self Built PC suddenly shuts down without warning, this has occurred randomly but is happening more often.
I have copied below the event logs at the time of the latest shut down in the hope you may be able to let me know what the problem may be and hopefully how to correct it.
They are all noted as the same time but I guess the last entry happened first.

Here we go:
[FONT=&quot]The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly. Other info on screen: LOG NAME System. SOURCE Kernel-Power. EVENT ID 41.LEVEL Critical. USER System. TASK CATEGORY (63) KEYWORDS (2).[/FONT]
[FONT=&quot]END
[/FONT]

[FONT=&quot]The previous system shutdown at 17:28:51 on ‎04/‎02/‎2012 was unexpected.[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The Windows Search service terminated unexpectedly. It has done this 8 time(s).[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The Windows Search service terminated with service-specific error %%-2147218174.[/FONT]
END

[FONT=&quot]The index cannot be initialized.[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The object you are trying to create already exists. Try again using a different name. (HRESULT : 0x80040d02) (0x80040d02)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The application cannot be initialized.[/FONT]

[FONT=&quot]Context: Windows Application[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The object you are trying to create already exists. Try again using a different name. (HRESULT : 0x80040d02) (0x80040d02)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The gatherer object cannot be initialized.[/FONT]

[FONT=&quot]Context: Windows Application, SystemIndex Catalog[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The object you are trying to create already exists. Try again using a different name. (HRESULT : 0x80040d02) (0x80040d02)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The plug-in in <Search.TripoliIndexer> cannot be initialized.[/FONT]

[FONT=&quot]Context: Windows Application, SystemIndex Catalog[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] Element not found. (HRESULT : 0x80070490) (0x80070490)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The plug-in in <Search.JetPropStore> cannot be initialized.[/FONT]

[FONT=&quot]Context: Windows Application, SystemIndex Catalog[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The content index catalog is corrupt. (HRESULT : 0xc0041801) (0xc0041801)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The Windows Search Service cannot load the property store information.[/FONT]

[FONT=&quot]Context: Windows Application, SystemIndex Catalog[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The content index server cannot update or access information because of a database error. Stop and restart the search service. If the problem persists, reset and recrawl the content index. In some cases it may be necessary to delete and recreate the content index. (HRESULT : 0x8004117f) (0x8004117f)[/FONT]
[FONT=&quot] END[/FONT]

[FONT=&quot]The search service has detected corrupted data files in the index {id=1100}. The service will attempt to automatically correct this problem by rebuilding the index.[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] The content index catalog is corrupt. (HRESULT : 0xc0041801) (0xc0041801)[/FONT]
END


[FONT=&quot]The Windows Search Service cannot open the Jet property store.[/FONT]

[FONT=&quot]Details:[/FONT]
[FONT=&quot] 0x%08x (0x8004117f - The content index server cannot update or access information because of a database error. Stop and restart the search service. If the problem persists, reset and recrawl the content in[/FONT][FONT=&quot]dex[/FONT]. [FONT=&quot] In some cases it may be necessary to delete and recreate the content index. (HRESULT : 0x8004117f))[/FONT]

END

I do not know where the above references are located, how to reset and recrawl the content is a mystery! This is really bugging me as I have lost a lot of work in one shutdown.

Check to see if the system is overheating. If unsure, point a house fan into the case on high and see if that improves things.

Then, start with these free hardware diagnostics: Hardware Diags

Its not a heat problem, 5 fans and an Arctic 13 cooler and not much loading, this is an Index problem going by the logs, I will see if I can rebuild the index and see if that sorts it.

It's your system and you know best.
Good luck to you!