How to Fix Vista SP2 "Checking for Updates..." Hangs and Slow Windows Updates

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Vista Pro
What Are the Symptoms?

There is currently a known issue on Vista SP2 computers where Windows Update can hang on "Checking for updates..." for several hours (or even days) without throwing an error message. This problem was first reported in August 2015 and these slow Windows Updates have become progressively worse over time. Extended support for Vista SP2 and IE9 ended on 11-Apr-2017 but many users have recently discovered that they still have a large backlog of available updates waiting to be installed because Windows Update has not run to completion for several months. Users who perform a clean re-install of their Vista OS will encounter these "Checking for updates..." hangs as soon as Service Pack 2 (SP2) is applied.

When one of these "Checking for updates..." hangs occurs the Windows Update Agent (wuaueng.dll) v7.6.7600.256, running under the Windows Service Host Process svchost.exe, will saturate an entire CPU core (e.g., 100% CPU activity on a single core CPU, 50% CPU activity on a dual core CPU). Affected users might notice a significant decrease in system performance or hear their cooling fan run constantly when their CPU begins to overheat but there is no network bandwidth consumption or rapid disk reads/writes associated with this problem. See Dalai's background information <here> for further details.

Note that MS Office 2010, MS Office 2007 and/or the MS Office Compatibility Pack SP3 (an add-on that allows older MS Office products to work with files with newer Open XML formats like .docx, .xlsx, etc.) also cause these "Checking for updates..." hangs, even if the Vista SP2 OS is fully patched to 11-Apr-2017.

How Do I Fix These "Checking for updates..." Hangs?

Step-by-step instructions are posted on page 1 of m#l's thread Updates not working, it has been searching for updates for hours in the MS Answers forum.

Users must download and run standalone .msu installers for the five so-called "speed-up" patches listed in STEP # 2 of those instructions [KB3205638 (rel. 13-Dec-2016); KB4012583 (rel. 14-Mar-2017); KB4015195 (rel. 11-Apr-2017); KB4015380 (rel. 11-Apr-2017) plus KB4014661 (rel. 11-Apr-2017) if IE9 is installed] if any of these security updates have not been installed by Windows Update. These instructions are based on the work of Dalai, who discovered that pre-installation of one or two security updates each Patch Tuesday [usually a Windows kernel-mode driver (Win32K.sys) update] would speed up Windows Update and posted his findings at Search for Windows Updates takes forever? - A possible solution.

If MS Office 2010, MS Office 2007 and/or the MS Office Compatibility Pack SP3 are installed then additional "speed up" patches for these Office products are listed in Volume Z's post on page 1 of peggybegg's thread why has vista stopped automatic updates?. Microsoft will continue to release security updates for these Office products beyond 11-Apr-2017 until they reach their end of extended support and Volume Z revises this list every Patch Tuesday (the second Tuesday of the month) with the KB numbers of any new Office "speed up" patches that must be pre-installed to speed up Windows Update.

Once all missing "speed up" patches have been pre-installed and Windows Update is able to run to completion and install your remaining updates then please read the supplemental thread More Shadow Brokers Exploits Patched June 2017 for Win XP and Vista. Five emergency out-of-band security updates were released for Vista SP2 in June 2017 to patch vulnerabilities for the NSA-leaked exploits EnglishmanDentist, EsteemAudit and ExplodingCan. These updates will not be delivered to Vista SP2 machines via Windows Update so standalone .msu installers must be downloaded and installed manually.

Where Can I Get More Help?

Post any questions or feedback in ScousaJAY's thread windows update just seems to hang while checking here in Vista Forums, or start a new topic <here> in the Windows Update board of Vista Forums.


All credit goes to Dalai for posting the original solution at Search for Windows Updates takes forever? - A possible solution, as well as MS MVP Woody Leonhard who alerted his readers to Dalai's solution in his Woody On Windows blog on ComputerWorld. Kudos as well to all the Vista SP2 users who ran monthly tests of Dalai's suggested "speed up" patches each Patch Tuesday and continue to provide their invaluable feedback in ScousaJAY's thread windows update just seems to hang while checking.
32-bit Vista Home Premium SP2 * Firefox ESR v52.6.0 * Norton Security Premium v22.11.2.7 * MB v3.3.1
HP Pavilion dv6835ca, Intel Core2Duo T5550 @ 1.83 GHz, 3 GB RAM, NVIDIA GeForce 8400M GS
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My Computer

System One

  • Operating System
    32-bit Vista SP2 Home Premium
    HP Pavilion dv6835ca
    Intel Core2Duo T5550 @ 1.83 GHz
    Quanta 30D2 (U2E1)
    3 GB RAM
    Graphics Card(s)
    NVIDIA GeForce 8400M GS
    Sound Card
    Realtek High Definition Audio
    Hard Drives
    250 GB SATA Western Digital Scorpio WD2500BEVS 5400 rpm
    Internet Speed
    5 MBps
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