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I just experienced something strange in Windows 7. I could hear how the harddrive was used at regular intervals of about one second. The same thing seemed to steal my CPU timeslice (from my own application) at about the same regular intervals. I opened up the task manager and started looking at the processes there, but could not find any offender. No single process had page faults of CPU usage that had the same regularity, but nonetheless I started killing off services, such as Windows Search, Windows Defender, and so on.

Eventually the disturbance went away by itself.

What I did see (I think) is that sometimes one process -- any one -- would spike page faults and/or CPU usage at about once every second. Which leads me to belive that the cause of this was a driver. Is there some kind of defragmenting driver (or at least some type of driver) that sometimes does hard drive reads/writes at intervals like this?

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To get more detailed information you can use a few Sysinternals tools.

For the CPU, get Process Explorer and let it run for a while. Then you can view the graphs to find out exactly which process was sucking cycles.

For the disk, get Process Monitor and select the file filter to view what files/folders are getting accessed (you’ll probably need to filter some stuff out to reduce the clutter).

To examine the drivers, services, and such, try Autoruns. Make sure to select the options to verify signatures and hide Windows entires to reduce the clutter so that you can focus in on the third-party stuff.

For the record, if the thrashing was happening in concert with a lot of page-faults, you may want to check to see if your pagefile is sufficient (is the disk running out of space?) and increase it if not. You may also want to consider putting it on a different physical drive. Either way, it could be something that is sucking up memory, causing the virtual-memory manager to kick in and flush stuff to the pagefile, thus causing the thrashing.

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Windows 7 does a lot of stuff with your idle processes. What your probably running into is SuperFetch. This handy feature is the sibling to XPs prefetch(which sucked). When your not using processes it attempts to load information off the disk it thinks your going to use so it loads faster. You can disable it and see for sure. As for what was taking processor power, I can't say. You can go through the process in the post by Synetech inc. if it happens again.

Windows 7, by default also has the defragger enabled and scheduled. You can check it out in the usual spot under accessories.

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Take a look at Windows 7's Resource Monitor tool (you can find it with a start menu search)

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