Checking for Available Windows Updates on Windows 7 Targets Takes Too Long!

If you’re experiencing *very* slow Windows Updates processing (scanning, downloading, installing) with Windows 7, in particular, you’re not alone.

For approximately a year now Windows 7 users have been struggling with very slow performance during the scan for Windows Updates. The issue occurs regardless of whether you check for updates using BatchPatch or directly on a target computer in the control panel Windows Update GUI.

The problem appears to mostly affect machines with slower CPUs. For example, in our lab here we have an old Dell Netbook with Intel Atom CPU. In the most recent test, it took 18 hours just to check for available updates! And no, that is NOT a typo.

It’s hard to say *exactly* why the process is so slow, but it’s likely a combination of complex rule processing for update revisions, superseded updates, and update expiration, along with inefficiencies in the Windows Update Agent code that causes it to require a lot of CPU time, especially for older/slower CPUs. The following links have some good information on the likely causes:

Over the past year Microsoft has released numerous updates to the Windows Update Agent, many of which were intended to address the slowness issue. However, here we are in April 2016, and the slowness is worse, not better. A year ago the same Dell netbook that took 18 hours to scan this month took only a few hours. And while a few hours is definitely NOT good performance by any means, it’s much better than 18 hours! Realistically though, the scan should only take minutes, not hours. Note, there does seem to be a correlation between the number of available updates and the time it takes for the scan to complete. For example, as soon as updates are installed on our lab Dell Netbook, the time it takes to check for updates drops to only a few minutes.

If you’re experiencing this slowness on any of your Windows 7 machines, there might finally be a solution!

The poster, EP, in the comments section on the following blog appears to have found the magic combination of updates required to fix the slowness.

He/she says:
"Install a COMBINATION of the following updates on Win7 SP1 -- KB3138612 AND KB3145739. I found out that patching KB3145739 alone without patching the WU Client for Win7 SP1 is not enough."

I can confirm that in our lab environment the machine that last week took 18 hours to scan for updates just now took only 10 minutes after installing both of the updates mentioned above. Also there have been numerous other reports from users around the web that this update combination worked in their environments to dramatically reduce scan times. Let’s just hope that it continues to hold up in the future.

2016-06-14 Update:

As of June 14th, the problem resurfaced, and apparently now you also need to install KB3161664 and possibly also KB3161608 to keep things moving. See for more information.

He/she says:
"The Windows Update search/scan 'forever' problem has once again resurfaced for Win7 SP1 as of June 14 (June Patch Tuesday). The KB3153199 Win7 updates are no longer doing the job. And once again a new win32k.sys security update (KB3161664) has been released (MS16-073), which supersedes/replaces KB3153199. Win7 SP1 users should now install KB3161664 to speed up Windows Update scans instead of KB3153199 as of today 6/14."

"It looks like Microsoft has released a more permanent fix to the problem KB3161647 which is part of the KB3161608 Update Rollup of June 2016. If KB3161664 win32k.sys fix is not installed, try installing the KB3161608 update rollup, which updates the WU client."

2016-10-19 Update:

Microsoft has written an article about this topic here:

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