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The system that I'm looking at is Windows 7, 32bit.

When the system boots up it spends a ton of time reading and writing to the DataStore.edb file which is located in Windows\SoftwareDistribution\DataStore directory. This makes the system run really slow for several minutes, probably about 10 if I'm honest. If you stop the Windows Update service, within a minute the system will stop reading and writing from the file and everything runs smoothly.

Things I've tried:

I've stopped Windows Update, deleted the file, rebooted, but when I do that Windows rebuilds the file until it's a few hundred MB in size. Once Windows is happy with whatever it's doing, it stops and my disk usage and cue drop down to normal levels and the system does whatever you want with plenty of speed.

I've booted into SafeMode and run several virus scans and Kaspersky's RootKit killer tool and nobody finds anything offensive.

What should I try next?

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migrated from stackoverflow.com Jan 21 '13 at 13:44

This question came from our site for professional and enthusiast programmers.

Will I be notified of this answer? –  limefartlek Jan 18 '13 at 23:48
Ha! I didn't think I'd get a response on this here, but a friend said to try anyway. Oh well. :) I tried. Thank you for your help. I did post the question on SuperUser.com today. –  limefartlek Jan 21 '13 at 18:28

4 Answers 4

I know it's way past the point of being able to provide a suitable solution for you now, but I have exactly the same thing with a Windows 7 machine at work. For future reference, you can always check the integrity of (/g) and/or defrag (/d) *.edb files with esentutl.exe.

e.g. esentutl.exe /d c:\Windows\SoftwareDistribution\DataStore\DataStore.edb

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Expanding upon @mafbailey 's answer (And a big thanks to you, as well!) make sure to open the command prompt as an administrator when utilizing the following command line action to have the appropriate file permissions.

I'd have been stuck had I not known =)

esentutl.exe /d c:\Windows\SoftwareDistribution\DataStore\DataStore.edb
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RAMMap showed that C:\Windows\SoftwareDistribution\DataStore\DataStore.edb mapped file was wasting 400 Mb of my precious RAM. Moreover Windows Update was constantly slowing down the system in process of updating that huge file.

esentutl.exe just reduced DataStore.edb size from slightly more than 600 Mb to slightly less that 600 MB and proved to be useless in my case.

http://juneyourtech.blogspot.com/2013/06/datastoreedb-and-windows-vista.html states that deleting this file is also not an option as Windows Update would rebuild it to the same size of next run.

So I had to completely disable Windows Update Service autorun. This greatly lowered waste of RAM, CPU and disk IO. The system is much more responsive now.

See also How to schedule download of windows 7 updates? for a way to launch update using Windows Task Scheduler.

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I have experienced the same problem with a slowly starting computer running w7 home edition. Opening email or firefox was frustrating.

On my computer, during start up, the anti virus program (windows essentials) seemed to be taking a lot of time on the datastore.edb file.

This link http://www.groovypost.com/howto/improve-pc-performance-stability-anti-virus-exclusions/ solved the slow start up problem for me. The solution basically involves telling the virus scanner (windows essentials) to exclude checking this file. I did the other exclusions on the windows files as well. (but i'm fine with the scanners checking my photos, even though they should be safe)

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