Hi maroner pierre,
Based on what you described, the missing Pin to Start option for individual Settings pages such as Windows Update or About does not necessarily indicate that your Windows installation is damaged.
As a practical workaround, you can create a shortcut to the Settings page you use frequently and pin that shortcut instead, where Windows permits it. I would not recommend reinstalling or repairing Windows solely for this behavior.
If having Pin to Start directly on individual Settings pages is important to your workflow, I’d also recommend submitting the suggestion through Feedback Hub (Win + F) so the Windows team can review it.
Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas.
I hope this helps clarify why troubleshooting the installation itself may not be the best direction here.