How to check Hard Disk

Sometimes our computers may be working slowly because of hard disk errors. At that time, we should check our hard disks are in good conditions or not. We can check our hard disks by the following ways.

1. We can use chkdsk in the command prompt. To use command prompt, please press windows key and s key together at the same time.
    The system will check hard disk at the next time restart.

2. We can use hard disk sentinel to check the performance and health or a hard disk.
    The performance and health of the first hard disk is in 100%. So, we can use it safely.
    I will insert the next hard disk into the computer. Although performance is in good condition, the health is not in good condition. So, we should not continue to use second hard disk anymore.

I've made a video about it. You can see it in YouTube.