What’s wrong with my computer?

Kedah<3: What’s wrong with my computer?
Yesterday this thing came popping up saying:
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How do I get rid of the System Defragmentation virus?
Yesterday, a pop up appeared on my screen saying:

“Critical Error
Hard Drive not found. Missing hard drive.

“Critical Error
RAM memory usage is critically high. RAM memory failure.

“Critical Error
Windows can’t find hard disk space. Hard drive error

“Critical Error!
Damaged hard drive clusters detected. Private data is at risk.

“Critical Error!
Windows was unable to save all the data for the file System326A8300. The data has been lost. This error may be caused by a failure of your computer hardware.

“Critical Error
A critical error has occurred while indexing data stored on hard drive. System restart required.

“System Restore
The system has been restored after a critical error. Data integrity and hard drive integrity verification required.

I ran a HDD Scan since it said was recommended but this critical error pop-up still won’t go away. I checked my hard drive and there’s still space. What should I do?

Answers and Views:

Answer by sunshine84
The problem is in HDD repair your hard disk or buy new one.

Answer by Wendy
Use these Tutorials …. to get rid of the System Defragmenter Virus
Remove System Defragmenter Virus (Uninstall Guide)
https://www.bleepingcomputer.com/virus-removal/remove-system-defragmenter

System Defragmenter Virus Removal – How To Remove The “System Defragmenter” Virus For Good From Your Computer

Hope it helps..

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Answer by Giedrius M
Do this:

1. Download CCleaner. Do a full system temporally file cleanup : https://www.piriform.com/ccleaner
2. Scan with good anti-malware programs and delete what they find. I recommend Spyware Doctor or Malwarebytes.
3. Then reboot.
Here full instructions : https://www.2-viruses.com/remove-system-defragmenter