Update index.md

Author: PowershellScripts

index.md

@@ -93,7 +93,7 @@ Links to my older Social Technet Articles:
 
 * [Office 365 PowerShell Troubleshooting: quick guide](https://social.technet.microsoft.com/wiki/contents/articles/32035.office-365-powershell-troubleshooting-quick-guide.aspx)
 * [Quick way to set up Office 365 tenant for testing](https://social.technet.microsoft.com/wiki/contents/articles/37130.quick-way-to-set-up-office-365-tenant-for-testing.aspx)
-* Customizing sign-in experience for external users
+* [Customizing sign-in experience for external users](https://learn.microsoft.com/en-us/archive/technet-wiki/51868.office-365-customizing-sign-in-experience-for-external-users)
 * Office 365 data loss protection: Prevent your SharePoint list from deletion using Powershell
 * Exchange Online: What mailboxes User has access to?