Unable to Extend C Drive in Windows 11? Causes and Solutions Explained

Updated by

Tracy King 

Last updated on April 24, 2024

Please provide the English content you want translated, and I'll promptly translate it into Chinese for you.

Want to extend the C drive? Read on to learn how.

It's very common to run out of space on the C drive. After using the same Windows installation for a long time, you may find your main partition filled with all sorts of things – programs, games, and hidden files.

Then, many of them start to encounter issues like decreased performance and constant lack of storage. Thus, they want to extend the primary partition but fail to expand the C drive in Windows 11. So, are you facing the same problem?

So, let's see how you can extend C drive space in Windows 11 without losing any data, time, and computer performance.

Why can't I extend the C drive in Windows 11?

If you come across the issue of unable to extend C drive in Disk Management, there can be several reasons behind it. The most common one is that there is no extra or unallocated space available on the physical drive. How to check? Please follow the methods below:

Step 1: Click the Start menu.

Step 2: Type disk management, and press Enter.

Step 3: Find the physical drive that contains the primary partition, in this case Disk 0.

Step 4. Look at the type, status, and space used on each disk. This operating system drive has no unallocated space remaining.

Here, we see that there's no room to extend it. So we can't extend this C: drive in the normal way, and if we tried, we would get an error message saying there's not enough space to extend the partition. So let's look for another solution.

You can learn how to check the total hard disk space in Windows 10 from this article - How to Check Total Hard Disk Size in Windows 10.

Can't extend C drive in Windows 11? Yes, there is a solution.

Now that we've identified some reasons why you can't extend C drive, let's try to find a solution. Is there one? Yes. We can get back to the disk management the same way.

Once we do, we can do a few things, such as:

1. Delete or shrink a volume using Disk Management. This is the most common method, and requires you to use the built-in Disk Management utility.
2. Extend C drive with non-contiguous unallocated space.
3. Resize partition to add space to C drive from another partition.
4. Enlarge C drive with free space on another physical hard disk.

The only downside to Methods 2, 3, and 4 is that they require a third-party tool. But that's not an issue because you can easily perform the operation with tools like Partition Master Professional.

This is because only the first step can be accomplished with the disk management utility mentioned above. For all other steps, you will need to use the Partition Master tool. Let's see how it's done.

#1. Shrink or Remove Adjacent Volumes to Extend C Drive

In order to have free space on the physical drive, it must have unallocated space. Since we have no one living on our hard disk, we will take some space from the “neighbor” partition.

We can delete or compress this neighbor partition to extend our C drive.

Once that space is freed, it can be added to the C drive.

#2. Extend C Drive with Non-contiguous Unallocated Space

The first thing you need here is to download the Partition Master tool. Remember, without the help of a third-party tool, it's not possible to add non-contiguous unallocated space to the system partition. So, once you have downloaded and installed the tool, you need to use it.

Step 1: Free up unallocated space on the C drive.

If there is no unallocated space on the system disk, go to the Partition Manager, right-click on the partition next to C: and select "Resize/Move Volume".
Drag the left border of the partition to shrink it and leave unallocated space behind your system C: drive, then click "OK".

Step 2: Increase the size of the C drive.

1. Right-click on the C drive and select "Resize/Move."

2. Drag the end of the System Reserved partition to the unallocated space, so that the space will be added to the C drive. Then click “OK”.

Step 3: Keep all changes to disk C.

Click “Apply” and then “OK” to save all changes and extend the System C drive.

As you can see here, it lists all of our physical drives, from which we can select the drive we want to use as unallocated non-contiguous space to extend Drive C:.

#3. Allocate Space from Another Disk to C Drive

One common issue with the inability to extend a C drive partition is lack of available space. If all the space on the primary drive is occupied, you can get storage space from another physical drive. However, for this step, you would need to use the “Allocate Space” feature of the Partition Master tool.

Step 1. Right-click on the D: partition with enough space, and select "Extend Volume."

Step 2: Select the target partition - Partition C, and then drag the partition panel to the right to add the free space from Partition D to Partition C. Then click “OK” to confirm.

Step 3. Click on “Execute Task” and then click on “Apply” to start the process of moving space from Drive D to Drive C.

You can allocate any amount of GB from one partition to another, in this case, from G to C. Therefore, you need to use Partition Master to extend C drive easily.

Step 4: Extend the C Drive on the Second Hard Disk

If you have only one physical drive/partition on your computer, you may not be able to extend it unless you have another physical drive to use. You might wonder if you can extend a primary partition on one disk from a second disk.

Yes, you would need to use a tool like Partition Master and use its options to extend C: from the second disk.

Step 1: Run Partition Assistant and enter the "Partition Management" interface. Right-click on C drive and choose "Data Migration".

Step 2. Select the data you want to migrate, then click "Next" to continue.

Step 3: Select the target partition to move and then click "Start" to perform the task.

< strong >Step 4. After the migration, you'll have more free space on Drive C.

This feature is only available in the Partition Master tool, so you'll need to download and install it.

Conclusion: You need the right tools and methods

The "Can't Extend C Drive in Windows 11" error is fixable, provided you use the right method. Hence, you can utilize the built-in Disk Management tool in Windows or install the Partition Master utility. It also serves as the best data erasure software.

For beginners, we recommend the latter, because it covers all partitions and ensures a smooth transition to larger ones.