http://support.microsoft.com/default.aspx?scid=kb;EN-US;318378

How to Reinstall or Repair Internet Explorer and Outlook Express in Windows XP
适用于
This article was previously published under Q318378
Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry

SUMMARY
This article describes how to reinstall or repair Internet Explorer 6 and Outlook Express 6 in Windows XP. You may have to do this if you are having problems with Internet Explorer or Outlook Express because of damaged files or missing registration information.

Important After you use the procedures in this article, you must reinstall any updates to Windows XP again. To reinstall Windows XP updates, visit the following Microsoft Windows Update Web site:
http://windowsupdate.microsoft.com/

MORE INFORMATION
If you are not already running the latest service pack for Internet Explorer 6, you can download and install the latest service pack instead of reinstalling your current version. For additional information about how to determine which version of Internet Explorer is installed, click the following article number to view the article in the Microsoft Knowledge Base:
164539 How to determine which version of Internet Explorer is installed

Note Internet Explorer 6 SP1 is included with Windows XP SP1 and Windows XP SP2. If Windows XP SP1 or Windows XP SP2 is installed on your computer, you do not have to download and install Internet Explorer 6 SP1. For additional information about how to obtain the latest service pack for Internet Explorer 6, click the following article number to view the article in the Microsoft Knowledge Base:
328548 How to obtain the latest service pack for Internet Explorer 6

To reinstall or repair Internet Explorer and Outlook Express, use the appropiate method while you are logged on as an administrator.
Windows XP, Windows XP SP1, and Windows XP SP2: Reinstall or repair Windows XP
To repair or reinstall Internet Explorer and Outlook Express in Windows XP, complete the following procedure while you are logged on as an administrator:
Use the System File Checker tool to scan all of the protected files on your computer:
Click Start, and then click Run.
In the Open box, type sfc /scannow, and then click OK.

Note that you may be prompted for the Windows XP or Windows XP Service Pack 1 or Windows XP Service Pack 2 installation media.
Test to determine if the issue is resolved. If the issue is resolved, skip the remaining steps. If the issue is not resolved, continue to the next step.
Complete an in-place upgrade of Windows XP, a repair of Windows XP, or reinstall Windows XP. For additional information about how to complete an in-place upgrade or repair of Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:
315341 How to perform an in-place upgrade (reinstallation) of Windows XP

To reinstall Windows XP updates, visit the following Microsoft Windows Update Web site:
http://windowsupdate.microsoft.com/



Windows XP SP2: Reinstall Windows XP SP2
For additional information about how to obtain and install Windows XP Service Pack 2, visit the following Web site:
http://www.microsoft.com/athome/security/protect/windowsxp/choose.aspx

For additional information about obtaining Windows XP service pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack


For additional information about installing Windows XP Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
875364 Detailed Windows XP Service Pack 2 installation walkthrough




Windows XP and Windows XP SP1: Edit the registry and install Internet Explorer 6
Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
When you try to reinstall the same version of Internet Explorer, you may receive the following error message:

Setup has detected a newer version of Internet Explorer already installed on this system.
Setup cannot continue.
To avoid this error message and reinstall the same version of Internet Explorer and Outlook Express, follow these steps:
While you are logged on as an administrator, click Start, and then click Run.
In the Open box, type regedit, and then click OK.
Locate the appropriate registry subkey, right-click the IsInstalled (REG_DWORD) value, and then click Modify.

To reinstall only the Internet Explorer 6 browser component on Windows XP, use the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{89820200-ECBD-11cf-8B85-00AA005B4383}

To reinstall only Outlook Express 6 on Windows XP, use the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{44BBA840-CC51-11CF-AAFA-00AA00B6015C}

Change the value data from 1 to 0, and then click OK.
Quit Registry Editor, and then install Internet Explorer 6.
To reinstall Windows XP updates, visit the following Microsoft Windows Update Web site:
http://windowsupdate.microsoft.com/

By default, Internet Explorer 6 is preinstalled in all versions of Windows XP and cannot be removed. To provide computer manufacturers more flexibility in configuring desktop versions of Windows XP, Microsoft has made it possible for OEMs, administrators, and users to remove user access to Internet Explorer while leaving the Internet Explorer code intact and fully functional to make sure the functionality of programs and operating system functions that rely on it. For example, Windows XP supports an "IEAccess=off" switch in the Unattend.txt file, and Internet Explorer has been added to the Add/Remove Windows Components section of the Add/Remove Programs tool in Control Panel. This does not reinstall Internet Explorer.
REFERENCES
For additional information about Windows XP Service Pack 2, visit the following Web site:
http://www.microsoft.com/windowsxp/sp2/default.mspx

For additional information about how to help protect your personal computer, visit the following Web site:
http://www.microsoft.com/athome/security/protect/default.aspx

The information in this article applies to:
Microsoft Internet Explorer version 6 for Windows XP SP1
Microsoft Internet Explorer version 6 for Windows XP
Microsoft Outlook Express 6.0 for Windows XP