Two utilities to look at, although the "Bad Block" error
in your other post is not good news.
1) If you want to dig deeper:
Try Autoruns from the MS Windows SysInternals site:
http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx
AutoRuns will show/list all apps/etc. that load/run when you first boot ...
(the 'Boot Execute' tab),
when you logon (the 'Logon' tab) and other programs that load
(grouped by labeled tabs) for easy viewing.
It also provides the ability to selectively allows you to stop
(use with care) any program that you don't want to load.
You can undo any changes you have made.
Note: To get additional details on an item in the list you can't
readily identify you may need to highlight the item (right click) and use
the 'Search Online' option to get the details,
especially useful for the more obscure items in the list.
2) Find and display a Process that could be the cause try Process Explorer:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
Once you have Process Explorer installed and running:
In the taskbar select View and check:
'Show Process Tree' and the 'Show Lower Pane' options.
Move your mouse cursor over any column in the right hand pane and
right click and check the following boxes:
'Command Line' and 'Version'.
Then expand the process named 'Explorer' (click on the + sign)
In the column on the left named 'CPU', look for any high CPU usage.
Next click on the CPU column to sort the processes by %CPU usage
(Highest to Lowest).
Move the mouse cursor over any process,
you should see a popup with some detailed info.
Then mouse over the process that's using most or all the CPU %.
Then click on that process to highlight it,
Now that it's highlighted, right click and from the options listed select:
'Search Online'.
This should display what out there on the web about that process.
You can also double click on any process to open up a more detailed
'Properties' window.
Note: some entries like Explorer, System/Services, and Svchost
may need to be expanded to show the detail (sub processes),
in this case click on the + located to the left of the entry.
An alternate method when using Process Explorer
is to double click on the Graph just below the Menu bar.
This will open the 'System Information' window, which has a larger display
of all three graphs. Move your mouse over any spike in the
CPU Usage graph to see what process/application or service is the cause
of the spike.
.