By Michael / Last Updated March 1, 2021


My C drive is nearly full and the Windows update installation keeps failing. Anyone gives any suggestions to fix the C drive Windows 10 issue?

- Question from Tina

Why Is My C Drive Full Windows 10

Do you see the notification “You are running out of space on Local Disk (C:)”? If so, you can find your C drive is full and also, may notice that the computer is running slower than before. Why does this warning pop up? What is eating up space on C drive? Here, I listed several common factors that may make the C drive space smaller.

1. Your system may be infected with viruses and malware that keep generating adverse files to the C drive.

2. Windows system-related files accumulate on the C drive.

3. There are more and more installed Apps, Windows inbuilt programs, and downloaded software on that drive.

4. User data including documents, photos, videos, and music are saved on the desktop that belongs to C drive.

There could be more reasons behind this issue but that is not quite important. What you should be concerned about now is how to solve this problem.

Solutions to C Drive Full Windows 10

If the C drive is full or nearly full, many issues could happen. For example, you may notice your computer is suffering from slow speed and also, there could be frequent system crashes. So, in the following contents, you’ll learn some basic and pragmatic ways to make the C drive return to normal.

Solution 1. Run Antivirus Software

Before trying to delete any files on your PC or make any changes to it, the first thing to do is to fully scan your system with some antivirus software like Windows Defender. Because once your PC is infected with virus, there is possibility that adverse files keep being written to your system.

Solution 2. Use Disk Cleanup to Clear Unnecessary Data

Over time, junk files like cookies and cache can get clogged up in C drive. In this case, the Windows inbuilt program Disk Cleanup may come handy to help you delete some unnecessary files.

1. In the search box on the lower left, type “disk cleanup” and hit “ENTER” to bring up the disk cleanup dialogue box.

2. Select drive C that you want to clean and hit “OK”.

3. Tick off those files you want to clean and hit “OK”.

4. You will be prompted to confirm the operation. Then, confirm it to proceed.

C Drive Cleanup

Solution 3. Use Storage Sense to Clean C Drive Regularly

Similar to Disk Cleanup, Storage Sense is also a Windows inbuilt program to help clean any of your drives but much more powerful and efficient because you can let it clean your computer at intervals.

1. In the start menu, select “Settings”.

2. On the page of Windows Settings, click on “System”.

3. Select “Storage” on the left side and toggle on Storage Sense.

Note: After you activate Storage Sense, it works only when your computer is low on space. To clean up unused and junk files now, select “Configure Storage Sense or run it now” and hit “Clean now”.

Storage Sense On (2)

Solution 4. Delete Unwanted Apps to Reclaim Disk Space

Some applications that you seldom use usually occupy quite a lot of storage space. At this point, you need to manually delete them to free up space.

1. In the search box, input “Control Panel” and hit “ENTER”.

2. In the popup window, hit “Programs”.

3. Select “Programs and Features”.

4. Then, all Apps on your computer are listed. Right-click the App you don’t want and select “Uninstall” to remove it from the computer.

Control Panel Delete App

Solution 5. Delete Hibernation (hiberfil.sys) Files to Get More Free Space

When your PC is idle, you can leave it in hibernate mode which uses very little power. Compared with shutting it down, hibernate mode makes the computer available much more quickly when you need it. It seems literally convenient for users but generates many files in your hard drives including the C drive. If you’re suffering from the issue “My C drive is full Windows 10”, you might as well delete all hibernation files on your PC.

1. In the search box, input “command prompt”, right-click on “Command Prompt” and select “Run as administrator”.

2. In the popup window, input “powercfg.exe -h off’ and hit “ENTER”.

After that, you can find there is more free space on your C drive.

Disable Hibernate

Solution 6. Enlarge C Drive with Free Partition Manager

If none of those methods mentioned above work and your Windows 10 C drive is still full, maybe it’s time to borrow some space from other drives. Of course, you can turn to Windows Disk Management for help but it has many limits, for example, it only supports resizing partitions in NTFS and RAW; moreover, it can only merge with unallocated space that is adjacent to it and on its right side.

Luckily, this time, this is a better alternative – AOMEI Partition Assistant Standard – which is free from these limits. With this powerful software, you can not only resize the C drive without caring about the location of the unallocated space, but also, you can perform operations including formatting partitions, creating partitions, and deleting partitions. Moreover, unlike some of its counterparts, this software doesn’t come with any bundleware and it’s totally free.

PS: If there is no unallocated space, you need to manually create one; If there is already one piece of unallocated space, you can jump to Step 4 directly.

Download Freeware Win 10/8.1/8/7/XP
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Step 1. Install and launch AOMEI Partition Assistant Standard. Then, all disks and partitions will appear on the interface.

Step 2. Right-click on the disk you want to shrink and select “Resize/Move Partition”.


Step 3. Drag the circle on either side of the green bar to determine the size of the unallocated space. Click on “OK” to proceed.

Drag The Green Bar

Step 4. Now, you can see there is a piece of unallocated space on the disk. Right-click on C drive and select “Merge Partitions”.

Merge Partition

Step 5. Tick off the unallocated space you just create and hit “OK”.


Step 6. Hit “Apply” on the upper left of the interface and then, hit “Proceed” to start the merging process.

Apply Proceed

Just wait a few seconds before it’s done.


How to solve the problem of C drive full Windows 10? In this post, 6 solutions are given. Just try them in order and hopefully, you can find your way out. As for AOMEI Partition Assistant Standard, if you want to see more features including allocating free space to C drive and wiping system disk , you should upgrade it to the pro version.