Unfortunately, the Windows Vista updates have been slowed down a lot. It will take hours for it to get past 0% on both the downloading and the installing. Believe me, they aren't stuck, but you'll just have to wait a while for it to make any progress.
These slow Windows Updates are currently affecting both Vista SP2 and Win 7 SP1 users, and the issue is being discussed in ScousaJAY's thread windows update just seems to hang while checking. As Sea Monster noted, if you leave Windows Update running for several hours and don't see an error message you might find that "Checking for updates..." will eventually run to completion and allow you to download available updates.
If that doesn't help, please see the step-by-step instructions I posted on 16-Jun-2016 in m#l's thread Updates not working, it has been searching for updates for hours in the Microsoft Answers forum for a possible workaround. This temporary workaround was also suggested in ScousaJAY's thread, but that thread was started in August 2015 and currently has over 200 posts so new visitors might have a problem finding relevant information. I'd still advise you subscribe to ScousaJAY's thread hread windows update just seems to hang while checkingand read through some of the recent posts by other users, though. It's one of the best sources of information I've found to date on these slow Windows Updates and any new developments will likely be posted there.
----------- 32-bit Vista Home Premium SP2 * Firefox v47.0.1 * NIS v22.214.171.124 * MBAM Premium v2.2.1
KB3102810 (Installing and searching for updates is slow and high CPU usage occurs in Windows 7 and Windows Server 2008 R2) was released 03-Nov-2015 and included an update for the Win 7 Windows Update Agent (WUA). This update only applies to Win 7 - there was no analogous patch released for Vista.
If you are a Win 7 user, please see Woody Leonhard's InfoWorld article Microsoft releases KB3161647, KB3161608 to fix slow Windows 7 update scans for details on the latest patch for the Win 7 Windows Update Agent. The KB3161608 June 2016 update rollup for Windows 7 SP1 included six hotfixes, including KB3161647 (Windows Update Client for Windows 7 and Windows Server 2008 R2: June 2016) that adds "an optimization that addresses long scan time for updates". Again, Woody notes in that article that "there's no analogous patch for Vista customers".
The current Windows Update Agent v7.6.7600.256 for Vista at C:\Windows\system32\wuaueng.dll has not been updated by Microsoft since June 2012. The instructions for Vista users posted on 16-Jun-2016 in m#l's thread Updates not working, it has been searching for updates for hours are based on Dalai's workaround at http://wu.krelay.de/en/ and include steps for installing any missing updates for the Windows kernel-mode driver Win32K.sys.
----------- 32-bit Vista Home Premium SP2 * Firefox v47.0.1 * NIS v126.96.36.199 * MBAM Premium v2.2.1
I have had Windows Update running for over 8 hours and it would not budge.
I'm going to run Windows Update in the background for a week to see if there is any progress. It's possible the problem or part of the problem is with the Windows Update server(s).
I have been thinking of Installing a Windows 8 Upgrade I purchased a while back. Windows 8 which has the same min. system recourse requirements. You can then upgrade free to Windows 10 until July 29th.
After performing a manually fix for Windows Update. I selected only one file for Word Viewer to download and install. It worked and I thought great, Windows Update is now fixed. After selecting four more Word Viewer updates and no dice. I have tried various selections such as updates for only Vista, optional update, etc. but no go.
Other things attempted to update Vista
1. Stand alone MSU installers: Hang and display a message "Searching for updates"
2. Microsoft Update Catalog: "Add" button will not respond
Microsoft Update Catalog - https://catalog.update.microsoft.com
Requires an ActiveX script to be installed and can only be accessed through Windows iExplorer. To access and install the ActiveX on my PC I needed to lower the iExlorer security settings. I also added Microsoft.com as a Trusted Site.
Windows update manual fix
1. re-Installed windows updateagent
2. Renaming the "SoftwareDistribution" folder...
3. Renaming the Catroot2 folder...
Type the following commands, and then press Enter after each command.
net stop cryptsvc
ren %systemroot%\System32\Catroot2 oldcatroot2
net start cryptsvc
4. Registering the files that are used by Windows Update and Microsoft Update...
At the command prompt, type the following commands, press ENTER after each command, and then click OK every time that you receive a verification message:
5. Starting the Background Intelligent Transfer Service, the Automatic Updates service, and the Event Log service.... (some or all may be already running)
At the command prompt, type the following commands, and then press ENTER after each command:
net start bits
net start wuauserv
net start Eventlog