Dear Jim Grimble
For Windows 11 version 24H2, the best place to obtain an official and safe copy is the Microsoft Volume Licensing Service Center (VLSC) or MSDN/Visual Studio Subscriptions, depending on what licensing your organization has. These portals allow you to download previous feature updates even after a newer release so you can still access 24H2 even though 25H2 is now the latest public release. If you're using Windows Update for Business or Intune, you can also target a specific feature update using the feature update policies, which will let you deploy 24H2 to devices that need it.
If you’re not seeing 24H2 available, let me know which licensing portal you’re using and I can help verify the catalog on your behalf. It’s also worth checking any download filters or product selections, since 24H2 builds appear under “Windows 11 Enterprise/Pro” with specific build numbers rather than the version label.