Resolves a publicly disclosed vulnerability in Windows Address Book that could allow remote code execution if a user opens a Windows Address Book file located in the same network folder as a specially crafted library file.

You may receive an error message that states that you must reinstall Outlook Express or reinstall the Windows Address Book. When you open Outlook Express, you may be able to receive e-mail, but you cannot send e-mail or reply to e-mail.

To troubleshoot these issues, follow the steps below. After you follow each step, test to see whether the Offline Address Book issue has been resolved. If the issue is resolved, it's unnecessary to continue to the next step. If the issue isn't resolved, proceed to the next step. Check whether the GAL is up to date.

There are different ways to remove apps and programs, so if you can't find the one you're looking for, you can try another location. Note that some apps and programs are built into Windows and can't be uninstalled. You can try to repair a program first, if it's just not running correctly.

In the Windows Security app on your PC, select App & browser control, or use the following shortcut: App & browser control. Smart App Control adds significant protection from new and emerging threats by blocking apps that are malicious or untrusted.

To resolve this problem, try to identify and remove deceptive software from your computer. To do this, use one or all the following methods. 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.

Real-time protection is a feature in the Windows Security app that continuously monitors your device for potential threats such as viruses, malware, and spyware. This feature ensures that your device is actively protected by scanning files and programs as they are accessed or executed.

Outlook Express mail folders, e-mail messages, and Address Book are missing after you upgrade to Microsoft Windows XP. This behavior occurs because the Windows XP file structure is different and the files for Outlook Express are no longer in the same location.

Get security info and tips about threat prevention, detection, and troubleshooting. Including tech support scams, phishing, and malware.

After October 14, 2025, Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes for Windows 10. Your PC will still work, but we recommend moving to Windows 11. Learn more. Note: Use these steps for Windows programs.