error :This VM is generalized. VM disk settings cannot be edited on generalized VMs.

Hello M.GUEND

If you have taken backups of the virtual machine before the sysprep operation, you can restore the virtual machine to a previous state using the backup. Here are the general steps to restore a virtual machine from a backup:

1. In the Azure portal, go to the Recovery Services vault that contains the backup of the virtual machine.
2. In the vault, go to the Backup Items tab and select Virtual Machines.
3. Select the virtual machine that you want to restore and click on the Restore VM button.
4. In the Restore Configuration blade, select the restore point that you want to use for the restore.
5. In the Restore Configuration blade, select the Restore Type as "Create new virtual machine".
6. In the Restore Configuration blade, specify the details for the new virtual machine, such as the name, resource group, and virtual network.
7. Click on the Restore button to start the restore operation. Once the restore operation is complete, you should have a new virtual machine that is restored to the state before the sysprep operation. Note that the new virtual machine will have a different name and IP address than the original virtual machine.

I hope this helps! Let me know if you have any further questions.

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