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How to Merge Unallocated Space in Windows 10 for a Large Partition

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    Why Need to Merge Unallocated Space

    Nowadays computer has become an indispensable tool to deal with some things in life and work, and the hard drive is widely used for data storage. You probably have heard some words: primary partition, logical partition, unallocated space and free space. Data are written to a partition, but unallocated space doesn't belong to any partition, and no programs or other data are allowed to be written to it. Usually, there is some free disk space on your hard drive. In order to make full use of disk storage space, you choose to add unallocated space to partition in Windows 10 or create a partition on the unallocated space.

    Generally speaking, you are able to benefit from the unallocated space on the hard drive in two situations. As time goes on, there are large amounts of data stored on your hard drive in Windows 10. Although this latest operating system gets some supports from many users all over the world due to its outstanding features, you still can't ignore low disk space issue, especially on system partition C. If there is unallocated space, to merge unallocated space with C drive could be a good choice. In addition, if there are two unallocated spaces which are not adjacent, to combine them could also be wise for better disk space usage. Today in this post, we will introduce you some information about how to make full use of free disk space in these two cases. Keep reading, please.

    How to Merge Unallocated Space

    Case 1: Merge Two Non-adjacent Unallocated Spaces

    As the first part shows, it is most likely that there are two unallocated spaces on the hard drive in Windows 10. Today we will show you how to merge two unallocated spaces to make full use of disk space in Windows 10 in three different situations.

    situation 1 Situation 1: Merge Two Separate Unallocated Spaces on the Same Disk

    A true example to prove that many users have this requirement:

    "Hello guys. I was wondering if you can help me out with this, I have two, unallocated spaces on my laptop and I want to merge them into one new partition. Bear in mind that I have basic disk partitioning, do I need to transition to dynamic and is it possible to loss some data in the process?"
    --from tenforums

    Two circumstances you need to combine two unallocated spaces:
    • You have saved a large amount of data on your disk but the data are various. And you want to store them in different categories, for example, movies in a partition and work documents in another partition. Then there is already one partition for work files, you want to create a new large partition for movies with two non-adjacent unallocated spaces. To merge them into one unallocated space and then create a large partition should be done.
    • Besides, your partition is almost full, but this drive is between 2 unallocated spaces. "Extend Volume" when right clicking the drive only gives an option to merge with the unallocated space on the right side. But you want to merge these two unallocated spaces with the partition.

    In these two circumstances, it is needful to combine two unallocated spaces. Let's look at a screenshot of the disk layout in Disk Management:

    two separate unallocated spaces

    From the figure, you see there are two unallocated spaces which are far away from each other. If you want to merge two unallocated spaces into one, this work is not simple. Windows 10 Disk Management doesn't allow you to perform this operation. In this case, to use a piece of third-party is worthy of being recommended.

    In the software market, there are various partition tools. Among them, MiniTool Solution Ltd. has released a professional and reliable program – MiniTool Partition Wizard. This partition manager is designed to have six editions, such as Free Edition, Professional, Pro Ultimate Edition, Server, Enterprise and Technician Edition. For a non-server user, MiniTool Partition Wizard Free Edition will be a good choice. This partition software enables you to move/resize partition, extend partition, format/delete/copy partition, and supports many basic and advanced partition management operations on basic disks as well as dynamic disks in Windows 10/8/7/XP/Vista. Before combining two unallocated spaces, you need to download and install our software to your computer.

    Step 1: Launch MiniTool Partition Wizard Free Edition, and then you will go to the main interface. Here many features about partition and disk management are listed. Please right click on E drive to select "Move/Resize" feature or select E drive to click "Move/Resize Partition" from "Change Partition" menu to interchange the position of partition E and its neighboring unallocated space in Windows 10.

    merge two unallocated spaces

    attention Attention:
    You probably are wondering MiniTool Partition Wizard provides "Merge Partition" but not using it to merge unallocated space here. Why? This feature is not able to be used to combine two unallocated spaces. It only allows you to merge two adjacent partitions that must be in NTFS file system. So here we recommend you to merge two unallocated space with "Move/Resize Partition" feature.

    Step 2: Then please move the entire partition towards the left side to leave the unallocated space behind the target partition. In this window, "Using Enhanced Data Protecting Mode" option is checked by default which ensures data safety when suddenly power outage appears in Windows 10.

    Tip: It's recommended to back up your data before moving or resizing the partition.


    Step 3: Select F partition, and then click "Move/Resize Partition" to interchange the position of F and its adjacent unallocated space.

    resize partition

    Step 4: Then in this interface, drag the partition handle to the left side or right side to combine these 2 unallocated spaces. Then, click "OK" to go back to the main interface again.

    combine unallocated space

    Step 5: Now you are able to see the original 2 unallocated spaces have been merged to one, but this is just a preview effect. And at last, you need to click "Apply" button on the top left corner to make all changes effective in Windows 10.


    tip Tip:
    Once the unallocated spaces are combined, you can use it to create a new large partition by using "Create Partition" feature of MiniTool Partition Wizard. However, sometimes unallocated space cannot create partition issue occurs due to maximum number of partitions error. Click here to learn much.

    situation 2 Situation 2: Merge Unallocated Space Windows 10 on a Disk Larger than 2TB

    In addition, there is another situation: if you use a hard drive which is larger than 2TB, it is most likely that your disk is divided into two unallocated spaces. Why? This is due to the limitation of MBR disk. Before using a hard drive, Windows will prompt you to initialize it to MBR or GPT and you probably choose MBR as the partition style. In fact, MBR only supports up to 2TB disk. If your disk is larger than 2TB, the rest disk space will show "unallocated" in Windows Disk Management. Look at the figure as follows to learn this situation in Windows 10:

    two unallocated mbr

    From the screenshot, you can see your 3TB disk contains two unallocated spaces. In this case, you need to merge them together so as to use all disk space on this hard drive. Do you know how to achieve this aim? Actually, it is very simple, and you only need to convert this MBR disk to GPT disk which supports up to 18TB hard drive.

    use Use Windows 10 Disk Management

    When it comes to the conversion between MBR and GPT disk, you will consider using Windows 10 Disk Management to perform this change. However, this free tool is not working. From the following picture, you know it doesn't allow you to directly do this conversion since "Convert to GPT Disk" feature is gray. This tool requires you to delete all partitions and then you can finish the change. However, all your data will get lost. So this way is not a good solution.

    convert to gpt

    run Run MiniTool Partition Wizard

    Fortunately, you can also use MiniTool Partition Wizard to merge unallocated space by converting MBR to GPT disk without losing data. Do as the following guidance shows:

    Step 1: Launch MiniTool Partition Wizard in Windows 10, and then in the main interface, you can see this 3TB disk shows only one unallocated space. Please right click on this target hard drive, and then select "Convert MBR Disk to GPT Disk" feature from the pop-up menu. Or after selecting the disk, click this function from "Convert Disk" menu.


    Step 2: Then click "Apply" in the last to execute this change. Then after opening Windows 10 Disk Management, the two unallocated space has been combined into one.

    only one unallocated space

    Now you can use Disk Management to create a new NTFS or FAT32 partition by right-clicking on this unallocated space to use "New Simple Volume". You can also use MiniTool Partition Wizard to create a new partition with the unallocated space. This free partition manager allows you to create a partition with file system including FAT, FAT32, exFAT, NTFS, Ext2/3/4 and Linux Swap.

    create partition

    situation 3 Situation 3: Merge Unallocated Spaces on Two Different Hard Disks

    Besides, you probably experience that two unallocated spaces are on two different hard disks.

    two unallocated on two disks

    If you want to combine them to create a larger partition, what should you do? In fact, it is simple. Look at the guidance below:

    1. Right click disk 1 and then select "Convert to Dynamic Disk" with Disk Management in Windows 10. Please repeat this operation to change disk 2 to dynamic disk.

    dynami disk

    2. Then create a spanned volume which can occupy the whole unallocated spaces on two hard drives. Right click one unallocated space, and then select "New Spanned Volume" feature. Then click "Next". Next, select and add unallocated space on another disk, assign a drive letter for the volume, format it to NTFS/FAT32, and finally click "Finish". Now dynamic volume L has been created on two unallocated spaces.


    In the above three situations, we introduce you detailed solutions about how to merge two unallocated spaces which are not adjacent in Windows 10. If you also have such a need, please choose an appropriate method according to your actual situation.


    Watch a visual video about how to merge two unallocated partitions in Windows 10:

    Case 2: Add Unallocated Space to Partition Windows 10

    In addition to combining two non-adjacent unallocated spaces into one for a large partition, you probably want to know how to merge unallocated space with partition, especially to C drive when system partition is running out of space. How to merge free space into primary partition by using Disk Management? Actually, you can only extend C drive with the unallocated space which must be closely followed by. If the unallocated space is far away from C drive, how to move unallocated space to C drive? Fortunately, MiniTool Partition Wizard Free Edition also enables you to do this work effectively with its "Extend Partition" feature. This function enables you to increase partition size by taking disk space from other partitions or unallocated space.

    Step 1: Run the Free Edition of MiniTool Partition Wizard to the main interface. Select partition C, and then click "Extend Partition" function under "Change Partition" menu in the action panel.

    add unallocated space to c drive

    Step 2: Then please choose to take free space from the unallocated space. By dragging the slider, you can decide how much free space you want to take. Here we suggest you to drag it towards right side to occupy the entire unallocated space. Then click "OK" to go back to Partition Wizard main interface.

    merge unallocated to c

    Step 3: Now you preview the unallocated space has been moved to C drive. Finally, make this change effective by hitting "Apply" button.

    move unallocated space to c

    recommend Useful Article: How to Merge C Drive and D Drive in Windows 10 without Losing Data

    Bottom Line

    In this post, we introduce why you need to merge unallocated space and the particular ways in two cases about how to merge two non-adjacent unallocated spaces in three situations and how to add unallocated space to C drive in Windows 10. With the help of MiniTool Partition Wizard Free Edition, you are able to combine two unallocated spaces into one for a bigger partition or expand system partition with ease. If you are interested in our software, please don't hesitate to download it for a free try. Besides, welcome to leave a comment below or email us via support@minitool.com.