how to fix windows10 accidentally switched off while restoring

Solution
That depends on what you were restoring and what you were using to do the restore. You haven't said either. E.g. If you were using Macrium Reflect to restore a full system backup, you could boot the Macrium CD and do the restore.
That depends on what you were restoring and what you were using to do the restore. You haven't said either. E.g. If you were using Macrium Reflect to restore a full system backup, you could boot the Macrium CD and do the restore.
 
Solution