Windows can’t check the disk while it’s in use

My system is very busy and doing very slow work. The hard drive is also giving a sound. I restarted again and again but system is too slow.
Some times, when I restart my system a hard disk error appears, "System can’t find your system Hard Disk".
Please tell me why I receive this error and how I can remove this error.

Microsoft Windows
Windows can’t check the disk while it’s in use
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