please help.... my pc has serious problem and i dont know how to fix it.

The Diagnostic Service Host Service Failed to start due to the following error:
The account specifield for this service different from the account specifield for other
service running in same proses.

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
  <Provider Name="Service Control Manager" Guid="{555908d1-a6d7-4695-8e1e-26931d2012f4}" EventSourceName="Service Control Manager" /> 
  <EventID Qualifiers="49152">7000</EventID> 
  <Version>0</Version> 
  <Level>2</Level> 
  <Task>0</Task> 
  <Opcode>0</Opcode> 
  <Keywords>0x8080000000000000</Keywords> 
  <TimeCreated SystemTime="2014-05-09T20:21:17.893756900Z" /> 
  <EventRecordID>573231</EventRecordID> 
  <Correlation /> 
  <Execution ProcessID="916" ThreadID="4576" /> 
  <Channel>System</Channel> 
  <Computer>PC001</Computer> 
  <Security /> 
  </System>
- <EventData>
  <Data Name="param1">Diagnostic Service Host</Data> 
  <Data Name="param2">%%1079</Data> 
  </EventData>
  </Event>