This article contains several methods that you can try if you receive the "0x800A138F" error message when you try to install updates from the Windows Update site. The article also contains advanced troubleshooting methods for the more experienced computer user.
This article is intended for a beginning to intermediate computer user. You may find it easier to follow the steps if you print this article first.
Because this problem can occur for several different reasons, you may have to work through more than one method to resolve the problem. However, we start with the simplest method, and we provide step-by-step instructions to guide you. If you cannot resolve the problem, or you feel that you are too inexperienced to try the advanced methods, we will tell you how to contact Microsoft for more support.
Before we get started, you must know which version of Internet Explorer that your computer is running. If you already know which version of Internet Explorer is running, you can go to method 1. Otherwise, follow these steps:
Start Internet Explorer.
On the Help menu, click About Internet Explorer.
The product and version information are displayed in the About Internet Explorer dialog box that appears.
Now that you know which browser version that your computer is running, you are ready to try method 1.
Method 1: Reset Internet Explorer settings
If the problem is caused by damaged or incompatible Internet Explorer settings or add-ons, you can usually resolve the problem by resetting Internet Explorer settings. When you reset Internet Explorer settings, all add-ons and customizations are deleted, and you basically start with a fresh version of Internet Explorer.
Resetting Internet Explorer settings restores the default settings of the following features:
Search providers, tabbed browsing settings
Colors, languages, fonts, and accessibility settings
Note By resetting Internet Explorer settings, you return Internet Explorer to the state it was in when it was first installed on your computer. Resetting removes any information that is stored in the settings that are listed in this section.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
The Reset Internet Explorer Settings (RIES) feature does not reset some settings in Internet Explorer 7
Did this fix the problem?
Check whether the problem is fixed by trying to install updates from the Windows Update site. If you can install updates from the Windows Update site, you are finished with this section. If the problem is not fixed, you can contact support
This section is intended for advanced computer users. If you are not comfortable with advanced troubleshooting, you might want to ask someone for help or contact support. For more information about how to contact Microsoft support, visit the following Microsoft Web site:
Method 2: Temporarily turn off background programs
Firewall or Internet accelerator programs may interfere with Windows Update. Even though you may have a firewall or Internet accelerator that was running for some time without any previous problems with accessing Windows Update, new updates for these programs can create unforeseen issues. Some common applications that may cause conflicts with Windows Update include the following:
NetZero HiSpeed accelerator
Netscape Internet Service accelerator
Telus Fast Dial up service
Sygate Personal Firewall
Norton Internet Security
Zone alarm Firewall
Call wave accelerator
You can temporarily disable these programs to see whether they are interfering with Windows Update. For more information about how to turn off these applications, see the product documentation that was included with the application, or contact the program vendor.
For information about how to contact your application vendor, visit the following Microsoft Web site:
If you turn off third-party background programs, and this does not enable you to successfully download Windows Updates, go to method 3.
Method 3: Configure proxy settings
Start Internet Explorer.
Click Tools, and then click Internet Options.
Click the Advanced tab, click to select the Use HTTP 1.1 and Use HTTP 1.1 through proxy connections check boxes, and then click OK.
Exit Internet Explorer.
Restart Internet Explorer, and then try to install updates.
Method 4: Manually set your proxy server address and port
To use this procedure, you must have information about your proxy server that only your system administrator or Internet service provider (ISP) can provide. Therefore, you may have to contact your system administrator or ISP before you continue.
In Internet Explorer, click Tools, and then click Internet Options.
Click the Connections tab, and then click LAN Settings.
Under Proxy Server, click to select the Use a proxy server for your LAN (These settings will not apply to dial-up or VPN connections) check box, and then click Advanced. Note If you do not use a proxy server, make sure that the Use a proxy server for your LAN (These settings will not apply to dial-up or VPN connections) check box is not selected.
Type the appropriate proxy server address and port in the Secure box, and then click OK.
Try to install updates.
Method 5: Register Windows Update engine files
If the system DLL files that Windows Update requires to run have not been registered correctly on your system, you can have problems with Windows Update.
To register the files in Windows Vista, follow these steps:
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, type notepad in the Start Search text box, and then click Notepad in the Programs list.
Copy the following commands, and then paste them into the Notepad file that is opened:
How to configure Internet Explorer to use a proxy server
If the information here does not help you resolve the problem or if you experience symptoms that differ from those that are described in this article, search the Microsoft Knowledge Base for more information. To search the Microsoft Knowledge Base, visit the following Microsoft Web site: