Plan for change: Updates to Windows 365 Custom Image Requirements

Starting January 2026, Windows 365 will validate new custom images to ensure FSLogix is not installed and Start menu links are under 3,000. Existing images remain unaffected. Admins may update image-building guidance but no immediate action is required unless reuploading images.

Summary

Windows 365 is introducing two new validation checks for custom images. These updates help ensure consistent provisioning behavior and maintain service performance.

These validations apply only to new custom image uploads. Existing custom images already in use are not affected.

[How will this affect your organization:]

Beginning January 2026, newly uploaded custom images must meet the following requirements:

1. FSLogix must not be installed

Custom images that include FSLogix will fail validation. Windows 365 manages user profile handling automatically, so FSLogix should not be included in customer-provided images.

2. Images must contain fewer than 3,000 Start menu links

Images with 3,000 or more Start menu items will fail validation. This limit prevents performance issues caused by extremely large Start menu structures.

This scenario is very uncommon in typical deployments.

What admins will see

If an uploaded image does not meet the new requirements, admins will see one of the following error messages:

• FSLogix detected
• Start menu exceeds 3,000 items
• Or both

No corrective action is required unless an admin chooses to update the image and reupload it.

[What you need to do to prepare:]

No admin action is required to maintain current operations. To prepare for this change, you may choose to:

• Review internal image-building guidance and update documentation as needed.
• Ensure new images uploaded after rollout meet the updated requirements.

Additional notes:

• Existing custom images continue to function without any changes.
• Current provisioning policies are not affected.
• Only new image uploads will undergo updated validation checks.