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 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 article number below to view the article in the Microsoft Knowledge Base:
Edit the Registry and Install Internet Explorer 6
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}
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/