To meet market demand for the high data density on the disk of a hard disk drive (HDD), reduction of disturbance causing track misregistration is needed. The main disturbance in HDDs in a server or a desktop PC is flow-induced vibrations caused by airflow due to the disk rotation. Generally, there are two kind of flow-induced vibration (FIV) of the structures inside a HDD. One is in-plane or out of plane vibration of the read/write component, i.e., the carriage. Another is out of plane vibration of the disk. In these experiments, we tried to reduce out of plane vibration of the disk and the carriage by making a simple structural change. The investigation is carried out to clear up a cause of FIV of the carriage. The result showed that the outflow from the disk region is strong and can be the cause of the out of plane vibration of both the disk and carriage. To counteract this fluid force, the plates were put against the disks to prevent wind disturbance. As a result, the flow-induced vibrations of the carriage and the disks were significantly reduced. Based on our results, we designed an anti-FIV structure.