How to troubleshoot problems connecting to Windows Update or to Microsoft Update

This step-by-step article describes how to troubleshoot problems you may have when you try to connect to Windows Update or to Microsoft Update. One or more of the following symptoms may occur when you try to connect to these Web sites:

• Only a blank Web page appears.
• The computer stops responding when you try to download a file from the site.
• You receive a scripting error message.
• You receive one or more of the following error messages:
  
  Message 1
  0x80072F78
  Message 2
  Error Installing Dependency
  Message 3
  An unknown error occurred
  Message 4
  You chose not to download the software controls or there was a problem with downloading the controls, in which case much of the Windows Update site or much of the Microsoft Update site will be unavailable to you. If you would like to download the controls now, please click Try Again below.
  Message 5
  Your Internet Explorer security settings are set to High. In order to use the Windows Update site or the Microsoft Update site, you need to set your security settings at medium. To change your security settings: From the View menu on the toolbar, choose Internet Options. Click the Security tab, and then select Internet zone in the drop-down box. Click Medium.
  Message 6
  Internet Explorer cannot open the Internet site address. A connection to the server could not be established.
  Message 7
  0x80070641

To resolve this problem, follow the procedures that are discussed in this article until you can successfully connect to the site. After you complete a procedure, try to connect to Windows Update or to Microsoft Update. If you still cannot connect to the site, continue to the next procedure. As you complete these procedures, try to determine the cause of the problem, and then use the procedures you have to use to resolve the problem.

Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

Examine the computer settings

Verify the language settings

1. Click Start, click Run, type inetcpl.cpl, and then click OK.
2. In the Internet Properties dialog box, click the General tab, and then click Languages.
3. In the Language list, make sure that the operating system language version is included. If the operating system language version is not on the list, click Add, click the language in the Language list, and then click OK three times.

Reset Internet zone security

1. Click Start, click Run, type inetcpl.cpl, and then click OK.
2. In the Internet Properties dialog box, click the Security tab.
3. In the Select a Web content zone to specify its security settings box, click Internet, click Default Level, and then click Apply to set this zone to Medium security.
4. Click OK.

Add the Windows Update Web site and the Microsoft Update Web site to the list of trusted sites

1. Click Start, click Run, type inetcpl.cpl, and then click OK.
2. In the Internet Properties dialog box, click the Security tab.
3. In the Select a Web content zone to specify its security settings box, click Trusted sites, and then click Sites.
4. In the Trusted sites dialog box, click to clear the Require server verification (https:) for all sites in this zone check box.
5. Add the following Web sites:
   • http://update.microsoft.com
   • https://update.microsoft.com
   • http://*.update.microsoft.com
   • https://*.update.microsoft.com
   • http://download.windowsupdate.com
6. Click OK two times, and then visit the Windows Update Web site or the Microsoft Update Web site to determine whether the problem is resolved.

Verify that your Internet Explorer settings are correctly configured

1. Click Start, click Run, type inetcpl.cpl, and then click OK.
2. In the Internet Properties dialog box, click the Security tab.
3. In the Select a Web content zone to specify its security settings box, click Internet, and then click Custom Level.
4. On the Security list, click Enable under Run ActiveX controls and plug-ins.
5. Under File Download, click Enable.
6. Under Java Permissions, click Medium safety.
7. Under Launching applications and files in an IFRAME, click Enable.
8. Under Active Scripting, click Enable.

Verify that the date and time are set correctly

1. Click Start, click Run, type timedate.cpl, and then click OK.
2. In the Date and Time Properties dialog box, click the Date and Time tab, and then set the correct date and time. To do this, follow these steps:
   1. In the Date box, click the current month in the month list.
   2. In the year list, click the current year.
   3. In the calendar, click the current date.
   4. In the Time box, click to select the hour, and then use the up or down arrow to adjust the hour. Repeat this procedure for the minute and second settings.
   5. Click AM or PM, and then use the up or down arrow to change to AM or PM.
   6. Click the Time Zone tab, and then click the time zone for your current location in the Time Zone list.
3. Click Apply, and then click OK.

Examine the Internet connection and LAN settings

Verify that you have an Internet connection

Try to log on to your Internet service provider (ISP) before you try to access the Windows Update site or the Microsoft Update site. When you use some ISPs, you must log on before you connect to a site by using a browser. When you log on to an ISP, TCP/IP loads and provides connectivity to the Internet. To connect to any Internet site, you must use a TCP/IP session.

Click to clear the Automatically Detect Settings and the Use Automatic Configuration Script check boxes in LAN settings

1. Click Start, click Run, type inetcpl.cpl, and then click OK.
2. In the Internet Properties dialog box, click the Connections tab, and then click LAN Settings
3. Click to clear the Automatically detect settings and Use automatic configuration script check boxes, and then click OK two times.

Verify that you can connect to SSL enabled Web sites

The computer uses a secure HTTP port to connect to Windows Update and Microsoft Update. To test whether port 443 is open, follow these steps:

1. Click Start, click Run, type https://www.microsoft.com:443, and then click OK.
2. If you cannot connect to s.microsoft.com, or you receive an error message, the port may be blocked.

Determine whether a file or a program is preventing you from loading the Windows Update site

To determine whether a file or a program is preventing you from loading the Windows Update site, you can use the System Configuration utility to perform clean-boot troubleshooting. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Turn off ad removal programs, Web accelerators, and antivirus programs

Turn off any ad removal programs, Web accelerators, and antivirus programs before you try to access the Windows Update Web site or the Microsoft Update Web site. These programs can cause script errors.

Repair files

Use System File Checker to repair damaged Windows files

Use the System File Checker tool to repair damaged Windows files. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Register DLLs

Note The following instructions assume that the computer is running a clean installation of Microsoft Windows XP. In other versions of Windows, make the following changes to the command path:

• In Microsoft Windows 98 and Microsoft Windows Millennium Edition, use windows\system instead of windows\system32.
• In Microsoft Windows 2000 or Microsoft Windows NT, use winnt\system32 instead of windows\system32.
• If you upgraded to Windows XP from Windows NT or from Windows 2000, use winnt\system32 instead of windows\system32.

If the operating system is installed on a drive other than drive C, change the drive letter in the following steps to the system drive.

1. Click Start, click Run, and then type the following commands in sequence. Press ENTER after you type each command.
   1. regsvr32 c:\windows\system32\vbscript.dll
   2. regsvr32 c:\windows\system32\mshtml.dll
   3. regsvr32 c:\windows\system32\msjava.dll
   4. regsvr32 c:\windows\system32\jscript.dll
   5. regsvr32 c:\windows\system32\msxml.dll
   6. regsvr32 c:\windows\system32\actxprxy.dll
   7. regsvr32 c:\windows\system32\shdocvw.dll
2. After you type each command, click OK to dismiss the RegSvr32 message window.

Change the Windows Installer service to manual startup mode

If the Windows Installer service is disabled, you will encounter errors when you try to update your computer by using Windows Update or Microsoft Update. To troubleshoot this problem, change the Windows Installer service to manual startup mode. To do this, follow these steps:

1. Click Start, click Run, type services.msc, and then click OK.
2. In the right pane, right-click Windows Installer, and then click Properties.
3. On the General tab, select Manual under Startup type, and then click OK.

After you complete these steps, the Windows Installer service can only be started by a user or a dependent service.

Additional analysis

If the problem still exists after you complete the steps in this Web site, you may have to obtain the following files for additional analysis:

• C:\Windows\Windows Update.log
• C:\Windows\WindowsUpdate.log
• C:\Program Files\WindowsUpdate\V4\Iuhist.xml

For information about how to contact Microsoft, visit the following Microsoft Web site:

For more information about Windows Update error or about Microsoft Update error, click the following article numbers to view the articles in the Microsoft Knowledge Base: