When you try to install Vista SP1 from windows update you may receive the error code 0x80073712

Getting the error code 80073712 when running Windows Update on a Vista Home Premium 32 bit system.
 

Option 1

So far have followed steps in this MS Support Article

also tried this other suggestion:

1. Click the Start icon and in the search field type "winsxs".
2. Double click this folder and scroll down to the file "pending.xml".
3. Right click it and select "Properties".
4. Under the "Security" tab, select "Advanced"
5. Highlight your User Account name from the list and click "Edit..."
6. Repeat 5.
7. Check the box marked "Full control". Then "OK" (x4).
8. You can now delete the file "pending.xml". Make a back up copy if
you wish and paste it somewhere else just in case!
9. Restart your PC (on boot up it should no longer say "Configuring
Updates..." any more).
10. Download the 'Windows Update Installer'
(»download.windowsupdate.com/v7/wi···ndalone/...).
Once downloaded, you may want to move it from your download folder to
somewhere else. Such as where the Windows Update File (wuapp.exe)
was to start with (C:\Windows\System32). Double click it
to install.
 

Option 2

This issue can be caused by the following factors:

1. The Windows Update service has been stopped.
2. Corrupted Windows Update Temporary folder.

In order to narrow down the cause of this issue and resolve it, please refer to the following steps. After finishing each step, please check the result again on the Windows Update website.

NOTE: Some third party programs can affect the Windows Update service. If you are running any third party applications such as Spyblocker, Internet or web accelerators (programs designed to boost the speed of the Internet connection), security or anti-virus programs (Norton, McAfee, etc.), I recommend we temporarily disable or shut them down and then try accessing Windows Update later. Please understand that we are disabling these programs only for the purpose of troubleshooting and we can re-enable these programs after we finish troubleshooting.

Step 1: Verify the relevant Windows Update services
=======================================
1. Click the Start Button, in Start Search box, type: "services.msc" (without quotes) and press Enter. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
2. Double click the service "Windows Update".
3. Click on the "General" tab; make sure the "Startup Type" is "Automatic" or "Manual". Then please click the "Start" button under "Service Status" to start the service.
4. Please repeat the above steps with the "Background Intelligent Transfer Service" service.

You can also temporarily stop these services, restart the computer, and then start these services again. If any service is missing or cannot be stopped or restarted, please let me know.

Step 2: Rename the Windows Update Softwaredistribution folder
================================================
This problem may occur if the Windows Update Software distribution folder has been corrupted. We can refer to the following steps to rename this folder. Please note that the folder will be re-created the next time we visit the Windows Update site.

1. Close all the open windows.
2. Click the Start Button, click "All programs", and click "Accessories".
3. Right-click "Command Prompt", and click "Run as administrator".
4. In "Administrator: Command Prompt" window, type in "net stop WuAuServ" (without the quotes) and press Enter.

Note: Please look at the cmd window and make sure it says that it was successfully stopped before we try to rename the folder. However, if it fails, please let me know before performing any further steps and include any error messages you may have received when it failed.

5. Click the Start Button, in the "Start Search" box, type in "%windir%" (without the quotes) and press Enter.
6. In the opened folder, look for the folder named "SoftwareDistribution".
7. Right-click on the folder, select Rename and type "SDold" (without the quotes) to rename this folder.
8. While still in the "Administrator: Command Prompt" window, type the command "net start WuAuServ" (without the quotes) in the opened window to restart the Windows Updates service.

Note: Please look at the cmd window and make sure it says that it was successfully started. However, if it failed, please let me know before performing any further steps and include any error messages you may have received when it failed.
 

Option 3 - original link

• Delete the file  C:\windows\winsxs\pending.xml
• Try Installing Updates again
• If you and access denied error message check and restore appropiate permissions