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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 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 today. – limefartlek Jan 21 '13 at 18:28

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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I tried this and I received the following message: Error: Access to source database 'c:\Windows\SoftwareDistribution\DataStore\Data Store.edb' failed with Jet error -1032. – Alf47 Jun 10 '15 at 14:20
@Alf47 Stop the Windows Update service and try again – drake7707 Jul 10 '15 at 13:14
@Alf47 You need to run Command Prompt as administrator to have access. – Igor Jerosimić Sep 2 '15 at 8:33

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. 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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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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Also stop Windwos update services from 900Mb => 898MB – Userpassword Oct 21 '15 at 19:40

Try installing Windows Update KB3050265, released 2nd June 2015.

This is optional so you may have to look for it in Control Panel > System and Security > Windows Update > Show all available updates > Optional, and manually install it.

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This didn't help, I already have that update and still wake-up from hibernation is slow, and restart even much slower. – Danijel Jul 2 '15 at 7:27

Fixing Windows Update, this method is for Windows 7

Go to Programs \ Accessories: Cmd prompt

Click the right mouse button and run as administrator.

In the prompt window follow the sequence below:

net stop wuauserv (after Enter)

net stop bits (after Enter)

In Windows Explorer:

Go to the folder windows\software distribution\download (delete everything in there)

Go to the folder windows\software distribution\DataStore (delete everything in there)

Go to the folder windows\software distribution\DataStore\Logs (delete everything in there)

Go to the folder windows\software distribution\PostRebootEventCache (delete everything in there)

The CMD prompt window:

net start wuauserv (after Enter)

net start bits (after Enter)

Sources:- /

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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 about "Improve PC Performance and Stability by Properly Configuring Anti-Virus" 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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Disabling Windows Update worked. instantly went from 98% CPU constantly to less than 30% (i have a lot of real programs running). Personally, i would rather take responsibility myself for updating windows when i have the time, instead of having it check whenever it feels like it, especially if its going to kill performance

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The question already says, "If you stop the Windows Update service, within a minute the system will stop reading and writing from the file and everything runs smoothly."  Are you adding anything to that? – Scott Oct 18 '15 at 17:13
Welcome to Super User! This is really a comment and not an answer to the original question. To critique or request clarification from an author, leave a comment below their post - you can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post. – DavidPostill Oct 18 '15 at 19:15

Microsoft released a new WindowsUpdate Client Update to fix the slow Update searching/Installation.

Installing and searching for updates is slow and high CPU usage occurs in Windows 7



This updates reduces the detection time and uses less RAM. So try it out

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warning: after installing this, Windows Update now does not work at all, it immediately gives error "WindowsUpdate_80244019" "WindowsUpdate_dt000" which I've been unable to solve – M.M Dec 25 '15 at 11:21
Uninstalling this update did return me to the previous situation I was in – M.M Dec 25 '15 at 11:27
@M.M error 80244019 means WU_E_PT_HTTP_STATUS_NOT_FOUND Same as HTTP status 404 - the server cannot find the requested URI (Uniform Resource Identifier). which av suite/firewall do you use? – magicandre1981 Dec 25 '15 at 15:51
MS Security Essentials, and no firewall . Rest of internet was working fine (including IE) – M.M Dec 25 '15 at 20:38
@M.M try at least the June 2015 version which first includes the memory usage fix: – magicandre1981 Dec 26 '15 at 9:44

I don't know why this says that I posted this in January 2013, this problem was only a few months ago in 2015. Ha!

Anyway - I'm sorry to waste everyone's time. For some reason I wasn't getting notifications about this thread until today, December 9, 2015.

I tried a number of things and ended up on the phone with the manufacturer of the device that this computer was within. It turns out that they have a bug in their implementation of Windows that causes this to happen. The only solution to the problem is to re-image the machine and hope it doesn't happen again.

This applies to Zeiss OCT machines for those who are wondering.

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