By Ivy / Last update September 11, 2020

Need to run CHKDSK Utility

During the process of using Windows, it is common to encounter the situation that Windows reports error and is no longer working normally as it is infected with virus or certain system file is deleted accidently. What should we do then? First of all, we can use Windows built-in utility Check Disk to check the hard drive preliminarily.

How to run CHKDSK utility?

CHKDSK is a command executed from command line to Check Disk program. In addition, it is a built-in system utility provided by Microsoft for Windows operating system, which including DOS to check file system integrity and bad sectors of the hard drive. CHKDSK can recover file system and logical & physical errors. So, what should we do to run CHKDSK?

1. Press Windows + R at the same time to open Run box.

2. In the pop-up Run box, input “cmd” and hit Enter to open command window, thus we can type DOS command.

3. In the pop-up command windows, type “chkdsk i: /f”, where “i” is the drive letter assigned to the partition that you need to fix. If you want to fix C: drive, replace “i” with “c”.

4. After input chkdsk i: /f, hit “Enter” key to commit the command.

Then, you can have a basic understating of the disk status. You might be told that the disk is without problem or the disk has been fixed; and some disk space parameters: how big the file is, and how many bad sectors the disk has.

Correcting errors detected in the uppercase file in CHKDSK

But you may find that during the process of using CHKDSK utility, Correcting errors in the uppercase File error message appears. What this error message means? At first, let’s us know what is “uppercase file”. In the NTFS formatted disk, an upper file named $UpCase is used to compare and sort file names. This system file is a list of all Unicode character in uppercase. The file is 128 KB in size and contains a Unicode uppercase conversion table.

The message that Errors detected in the uppercase File while running CHKDSK utility can be regard as a warning. If such error appears every time when you run Check Disk utility or start Windows operating system, you may need to repair your computer as soon as possible. If it is not fixed in time, data may be lost.

Usually, running CHKDSK to repair system files won’t cause your system unusable, but if you run CHKDSK to fix system file errors, it is possible to delete some files on your hard drive. CHKDSK is aimed at ensuring that all information in the file is in a consistent state and it will not recover deleted or lost files. Since some files can be deleted by CHKDSK, if you want to restore CHKDSK deleted files, you should have a backup. If you forget to back up your data before running CHKDSK, chances are that your important data will be lost.

Backup files via AOMEI Backupper

To backup files, you can apply this simply and effective way.

Step 1. Free download AOMEI Backupper Standard from its official website and install it according to prompts.

Download Freeware Win 10/8.1/8/7/XP
Secure Download

Step 2. Run AOMEI Backupper, click “Backup” and choose “System Backup or “Disk Backup” based on your own demand.

System Backup

Step 3. Follow the prompts given by this software to choose source disk or partition and the destination path to save backup file. Then, click “Start Backup” button.

Select Destination

PS.: You can gain scheduled backup by clicking Schedule button. Here are five types listed: Daily, Weekly, Monthly, Event Trigger, USB plug in. But for the last two options, you need to upgrade AOMEI Backupper to Professional version.

Schedule Settings General

Then, you are able to restore the files deleted by CHKDSK.


You are able to turn the help of CHKDSK utility to check the hard drive that Windows installed on if you Windows operating system doesn’t work normally. But there are chances that you encounter CHKDSK: Correcting errors detected in uppercase file, which may delete certain files. Therefore, it is highly recommended to complete backup before running CHKDSK to avoid data loss.