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I have a Windows 7 computer that I use almost exclusively for streaming video (Hulu in Internet Explorer, or recorded or live broadcast TV with Windows Media Center). Often the computer freezes for a number of seconds. The hard disk light is on continuously during this time. It seems to happen a lot when I begin to watch something or after pausing the video.

Following the advice in this thread,

How do I troubleshoot a Windows 7 freeze or slowness?,

I have installed Windows Performance Analysis Tools and run the xperf command until a freeze occurs.

If I am interpreting the results correctly, the disk activity appears to correspond with the System process having a large flush count and flush service time. This is being done by a component with an unknown path tree and path name.

I have posted a set of log files here: Files

So, what do I do with this information?

Update: 1/19/14: I should probably add that there have been three BSODs in the last month--two of them in the last week. That is a much newer problem than the freezing, although it seems to point to memory or HDD problems. But as I have said in the comments below, I have run MemTest and disk diagnostics without detecting any problems. I have added the latest BSOD dump file to the collection of posted files FWIW. And there has been an ongoing problem since I bought the computer where it freezes up when coming out of standby; I have to force a restart. All of these have been random incidents that are hard to troubleshoot, and may or may not be related.

Update: 1/29/14: I have found that the problem continues even if I do a clean boot. Is it possible that it is related to the volume of data on the HDD? I have about 300 Gb of recorded TV on the drive. They are mostly half-hour to two-hour programs, so they are large files--anywhere from 3 to 25 Gb each. They should be contiguous files; defragmenting doesn't make much of a difference in performance.

There's one other interesting piece to the puzzle: It never happens when Windows Media Center is recording. The recorded shows do not have breaks or freezes, and we can watch other video during recording without any freezing. Either Media Center commands full priority and doesn't allow interruptions, or perhaps it is somehow the cause of the freezes during playback. Or, consistent with Zero3's suggestion below, maybe the constant activity during recording prevents the drive from spinning down.

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This type of behavior normally is explained by a HDD with lots of reallocated sectors. In other words your HDD is having to move data around to another sector because the original sector is considered bad by its firmware – Ramhound Jan 17 '14 at 16:49
Check out this answer (linked in the comments on the question/answer you linked):… – Ƭᴇcʜιᴇ007 Jan 17 '14 at 16:52
Thanks for the suggestions. I had previously run diagnostics on my HDD using Western Digital Data Lifeguard Diagnostics and Acronis Drive Monitor. Both have reported a healthy drive. Is there something else I need to do to check it? I also read the referenced answer and that was how I arrived at the conclusion that a large flush count and service time was the cause of the freezes. – Cliff Jan 17 '14 at 17:12
how much RAM do you have? – Keltari Jan 17 '14 at 17:26
I have 6 Gigabytes – Cliff Jan 17 '14 at 17:31

I think it is very premature to declare the disk dead as @Ramhound seems to suggest in the comments. This seems to be pure speculation, especially considering your perfectly fine S.M.A.R.T. status with zero reallocated sectors.

I have another guess that I believe is a lot more plausible: Your disk is spinning down/head parking due to inactivity and then takes a significant time to spin up again upon next access (the disk "flushing" you are seeing). This "feature" saves power, but can cause lag spikes of the kind you describe while the OS waits for the disk to wake up. This is unfortunately a quite common problem with WD's green "eco-friendly" product line which your drive belongs to.

It is possible to change and/or disable this "feature" on some drives using tools available from the WD website.

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I agree that there is little evidence of a hard drive failure. It has passed every test with flying colors. I looked at WD's web site, though, and it says that all drives spin down after 10 minutes and that cannot be disabled. The problem can appear in a lot less than 10 minutes, which makes me think that is not the cause. I can't find any options related to spin up or down in the BIOS. W7 is set to power down the HD after 20 minutes, so I don't think that's the cause either. I am posting some additional info in my original question. – Cliff Jan 29 '14 at 19:41
While WD might not acknowledge such, there is plenty of evidence of the contrary. I personally have a "green" drive with the same issue (spindown/head parking after less than a minute of inactivity and spinup time of at least a couple of seconds). Here is a link to one of many threads by people with similar issues:…. You might want to try some of the tools linked from that thread and see if any of them makes a difference (or at least can confirm whether this is the cause of your issues). – Zero3 Jan 30 '14 at 11:29
For further evidence and discussion, you might want to also check out this mega-thread which also is linked from my link above:… – Zero3 Jan 30 '14 at 11:32
No luck running the WDIdle Disable Tool (even from an elevated command prompt). The discussion in your first thread link suggests that it only works with external hard drives, so I would have to remove the drive from the computer, put it in an enclosure, and connect it to a USB port (probably on another computer). Doable, but a bit scary. CrystalDiskInfo reports Automatic Acoustic Management is off--changing the value or clicking Enable or Disable has no effect--and Advanced Power Management is grayed out. I can't figure out how to use the tools to tell if the drive is spinning down. Any tips? – Cliff Jan 30 '14 at 14:39
I'm afraid I can't help you any more than that. I gave up around the same point with my disk (I did manage to read the APM timeout value to confirm the issue, though. Not sure why you are not allowed to do so.) and bought another. No tools, including WD's own, was able to disable the "feature". I can't think of any other way of easily confirming whether this is the issue - besides an old-fashioned stop-watch and taking notes of time between disk activity. Good luck with the troubleshooting anyway! – Zero3 Jan 30 '14 at 15:30

Well, even though none of the disk diagnostics turned up any evidence of malfunctions, it appears that Ramhound was right that the HDD was causing the problem. I eliminated all other possibilities. First I disabled the write cache, figuring that doing so would stop the flushing activity. It did, for the most part, but then I was seeing high levels of writing to MFT and $LogFile. So I did a factory reset, hoping that overwriting the disk contents might clear out any corruption in the file system. The high disk activity persisted even after that. That pretty much narrowed it down to a hard disk problem. So I replaced the disk and did a clean install of Windows 7. That created a few problems of its own with missing drivers, but I was eventually able to recover the ones I needed from the old installation. The computer is working perfectly with the new HDD (and I have re-purposed the old one as an external back-up disk).

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