By Jessie / Last update November 7, 2022

Why C Drive is Full?

If your C drive is full causing your computer to run out of free space, you may not be able to install Windows updates and your computer's performance may be affected. There are many reasons for the “C drive is full for no reason” problem, and this article summarizes the common reasons below.

  • Viruses and malware may keep generating files to fill up your system drive.
  • You may save large files on the C: drive without realizing it. For example, the default downloads folder is located in the C: drive.
  • Page files, previous Windows installations, temporary files, and other system files may have taken up space on your system partition.

How to Fix C Drive is Full Easily

Recently, more and more users are reporting similar problems, such as "my C drive is full without reason Windows 10", "C drive is full Windows 10", etc. To solve this kind of problems, there are several ideas for fixing it. And this article list these ideas below.

  • Run Disk Cleanup for C drive: First, you can perform a disk cleanup on the C drive to free up more space.
  • Scan your computer for malware or virus: If the C drive is full for no reason due to malware and viruses, you can scan your PC for malware or viruses.
  • Check C drive for disk errors: Disk errors can also cause this problem, so checking the C drive for disk errors is also a way to go.
  • Check the hibernation file: The accumulation of hibernation files can also lead to the "C drive is full" problem, which is common in laptops, so checking for hibernation files is also necessary.
  • Delete huge files on C drive: If there are many huge files in the C drive, the C drive will face the problem of running out of space very quickly.
  • Clone the system disk to a larger one: If you are looking for the easiest solution to solve the low disk space issue, you can try to upgrade the system disk to a larger disk by a free disk cloning software - AOMEI Backupper Standard.

Clone

Once you understand the cause and solution ideas, you can continue reading to learn the detailed information. Each method will contain a specific graphic tutorial.

Fix 1. Run Disk Cleanup for C drive

When your C drive is full for no reason, you can first try to clean up your C drive by running Disk Cleanup. You can follow the steps below.

Step 1: Press Win + E to open the File Explorer, right-click on your C drive and select Properties.

Step 2: When the Properties window opens, click the Disk Cleanup button.

Click Disk Cleanup

Step 3: After the Disk Cleanup is opened, select the file types that are taking up a lot of space on your C drive, including previous Windows installation, system restore points, Recycle Bin, Temporary files, etc, and then click OK to clean them all.

Clean System Files

Typically, this helps you free up at least a few gigabytes or more of free space on your C drive. However, if this doesn’t help you much, you can try the next method.

Fix 2. Scan Your Computer for Malware or Virus

Virus and malware may constantly generate files to fill your C drive. So, when the C drive is full for no reason, malware or virus infection may be one of the causes. You can scan your computer from Windows Defender or any other antivirus software you are using. Once malware or virus is found, remove it so that your problem can be fixed.

Click Virus And Threat Protection

Fix 3. Check C Drive for Disk Errors

If no malware or virus is found, check your C drive for file system errors that might cause your hard drive to show wrong disk usage. You can follow the steps below to fix C drive is full in Windows 10. 

Step 1. Type cmd in the search box next to the Windows icon and then press Enter. This will open the Command Prompt.

Step 2. In the Command Prompt window, type chkdsk C: /f /v /x and press Enter. This will start checking your C drive for errors and fixing them.

Check C Drive For Errors

Step 3. If it does not start checking disk errors but instead shows the following message, type Y and hit Enter, so it will start checking your C drive the next time your Windows 10 restarts.

Type Y

Fix 4. Check the Hibernation File

For laptops, the hibernation file is often the culprit of a full C drive, because it needs to be as large as the amount of memory. The hibernation file can only survive in the C drive and it cannot be moved to other data drives. For this reason, you can follow the steps below to check the hibernation file.

Step 1: Type folder options in the search box next to the Windows icon. When the File Explorer Options appears in the result list, click on it to open the File Explorer Options window.

Step 2: Select the View tab. Check the Show hidden files, folders and drives box and uncheck the Hide protected operating system files (Recommended) box, then click Apply. This will show the Hibernation file which is hidden by default.

Show Hibernation File

Step 3: Open your C drive in File Explorer and now you can find the Hibernation file (hiberfil.sys) under the root directory of the C drive. Right-click on the hiberfil.sys file and select Properties to check how much space it is taking up on your disk.

Hyberfil

Step 4: Delete the hiberfil.sys file if it is taking up vast quantities of space. This will free up at least a few gigabytes of space on your nearly full C drive.

Fix 5. Delete Huge Files on the C Drive

You may have saved large files to your C drive and you don't notice it. Also, sometimes, if a program performs poorly, it may make an infinite number of files until your C drive is full. You can follow the steps below.

Step 1. Press Win+E to open your in File Explorer, find the C drive and make sure the Hidden items box under the View tab is checked.

Tick Hidden Items

Step 2. Type size:gigantic in the search box in the upper right corner. File Explorer will search all giant files on your C drive. When the searching is complete, you can get a better idea of what files are taking up most space and causing your C drive to be full.

Type Size

Step 3. Delete those unwanted huge files and empty the Recycle Bin. Or, move the large files to another data drive if you still need them. After that, you should see a few more gigabytes of free space on your C drive.

Fix 6. Upgrade System Disk to A Larger Disk (Easiest)

If you find that your C drive often runs out of space, or the above methods can't solve your problem completely, you can try to upgrade your system disk to a bigger one, which is the easiest and most long-term effective way to solve the “C drive is full” problem.

The free disk cloning software AOMEI Backupper Standard can help you easily clone the disk containing your system to a larger one. In this way, you will not only solve the “C drive is full" problem, but also don't need to delete the data on the source disk. As a professional disk cloning software, AOMEI Backupper Standard has these other advantages below.

Ensure secure boot: After cloning you will be able to boot your system directly from the cloned disk.
Intelligent clone: Under the default mode, it only copies the used sectors so that you can make full use of the free space on the target disk. If the source disk has bad sectors, it can clone bad sectors disk by skipping them automatically.
Live clone: The software allows the cloning tasks to run in the background so that you can use your computer normally during the cloning process.
SSD alignment: If your target disk is an SSD, this feature can accelerate the reading and writing speed of it.
Sector by sector clone: If the target disk is the same as or larger than the source disk, you can use this feature and it will clone all sectors whether they are used or not.
Multiple paths: It supports cloning the system disk to multiple destination locations, such as local disk, external disk, USB drive, etc.
Different system: It supports Windows 11/10/8/7/XP/Vista, etc.

If your target disk is not empty, remember to backup the important files on the target disk in advance, because the target disk will be erased during the cloning process. Then you can follow the graphic tutorial below.

Step 1. Download AOMEI Backupper Standard, install and open it, click Clone > Disk Clone.

Download Freeware Win 11/10/8.1/8/7/XP
Secure Download

Disk Clone

Tip:

The free version only supports 2 types in the free edition. One is MBR to MBR (system disks), the other is data disk clone. If you need to clone GPT to GPT, MBR to GPT, or GPT to MBR, you can upgrade to the professional version.

Step 2. Choose the original disk as the source disk. Then, click Next.

Select Source Disk

Step 3. Choose the larger disk as the destination disk. Then, click Next.

Select Destination Disk

Step 4. Tick the Sector By Sector Clone feature, since you need to clone a small disk to a larger disk. Confirm your operations and click Start Clone.

Start Clone 3

Notes:

  • Edit Partitions: You can change the partition size using this feature (advanced version).
  • SSD Alignment: If your target disk is an SSD, you can tick the SSD Alignment option to accelerate the reading and writing speed of the SSD.

Summary

This article shows the causes of the “C drive is full” problem and 6 different ways to fix it. If you encountered this problem, you can try these methods in turn to help you. One of the easiest ways is to clone the system disk to a larger one, so that you can get more disk space without deleting the data on the C drive.

The free disk cloning software AOMEI Backupper Standard can help you achieve the goal with just a few clicks. More importantly, after cloning you can boot your computer directly from the cloned disk.

In addition, it also provides System Clone and Partition Clone functions to meet your various cloning needs. You can download this software to discover more useful functions.