Friday, 25 January 2013

Speeding up the indexing service in Windows 7

I found myself in a situation where i wanted to increase the priority of the indexing process performed by the Windows Search service in Windows 7.... to cut a long story short I decided to rebuild the index.
It did most of the documents fairly quickly, but Outlook indexing was taking forever. I pretty much always have Outlook open which makes the indexing process proceed slowly to avoid causing problems for the user while indexing takes place.

The problem with that is that you can't search your email properly until the indexing is complete... Outlook warns that you're unlikely to get proper search results and can tell you how many items are left to index, in my case around 25000.

In earlier versions of Windows it was possible to easily tweak the registry in order to stop the indexing service from slowing down when it detected user activity. 
Things have changed a bit in Windows 7. For a start the likely candidate registry key, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\Gathering Manager, has a set of permissions that make it obvious that you really shouldn't be playing around with these registry entries.
You can work around the permissions issues, by impersonating the user TrustedInstaller, using a nifty piece of software called devxexec, however there is little point in doing so.
Modifying the DisableBackOff and DisableBackOffOnUser entries under the Gathering Manager key made no discernible difference to the indexing speed and the Indexing Options dialog continues to display a message indicating that it is indexing at reduced speed due to user activity.

After much googling on the topic I was not left with any clear answers, however some posts had mentioned using Group Policies on domain-linked computers in order to achieve the same result.
Start > Run > gpedit.msc
This will open the Local Group Policy Editor. Looking under 
Computer Configuration > Administrative Templates > Windows Components > Search
you can see there is an entry called Disable indexer backoff. Double click the entry and choose Enable, then click OK.

After a restart I opened the Indexing Options dialog and once the Windows Search service had started up it began indexing. I opened Outlook and a few other programs and it appears that it no longer slows down.



  1. I've seen your post multiple times by other people. However, I have windows 7 home and am unable to locate gpedit.msc so I believe that this program doesnt come with the home version. Any other way of speeding up indexing? It's really annoying

    1. Hi Michael,

      You are correct that Win 7 Home doesn't have group policy features. I found this website which offers a tool to install the group policy components in Starter and Home editions of Win 7, but I have never tried doing anything like that so I have no idea whether it will work, or if it might break anything.