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How do I use an “unallocated space” partition in Windows 7?

What does “unallocated space” on a hard drive mean? Is it just sitting there, waiting to be used when needed or what? My hard drive is now divided into two halves of 250GB each. I would like to have the whole hard drive clean and free. I searched your archives but there is nothing on deleting a stuck partition.

Well, in a sense, it is just sitting there, waiting to be used. The problem is that it’s waiting for you to tell it how it should be used.

Basically, you have an empty, unused partition and you need to decide how you would like that space to be used. Then, you need to tell Windows to use it.

Fortunately, this is pretty simple in Windows 7 and doesn’t require any additional tools; basic partition management and rearrangement is built right in.

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Fire up the disk manager (right-click Computer, click Manage and then click Disk Management), and I’m guessing that you’re looking at something similar to this:
Hard disk split into three partitions, one of which is 'unallocated'
That line represents a single physical hard disk that is divided into three partitions:

  • System Reserved – You may have something like this, a recovery partitions, or perhaps nothing at all.
  • C: – This is the partition that contains your C: drive.
  • Unallocated – This is the partition in question.

That unallocated partition represents disk space that will not be used until you allocate it. There are typically two approaches.

Format it as an additional drive

A very common approach is to simply create a new drive out of the unallocated space.

Right-click that Unallocated drive and click New Simple Volume…
Create a New Simple Volume out of unallocated space
This starts the “New Simple Volume Wizard”. Click Next on the resulting dialog to be taken to the page where you specify the volume size:
Specifying the size of the new partition
The default answer is to use all of the available space, which is probably what you want. If you want to break the unallocated space into multiple drives, you might choose a smaller size.

Click Next and you’ll choose the drive letter to be assigned to the new partition:
Specify the drive of the new partition
Once again, the default is probably appropriate, unless you have a specific reason to change it.

Click Next and you’ll specify formatting options:
Specify the format of the new partition
The answers to the default are typically appropriate, although this is a good time to specify the Volume label.

Click Next to get a summary screen for confirmation, and then Finish to complete the operation. Windows then formats
the drive and when complete, it appears as “just another drive” on your system:
New E: partition in disk manager
You can begin using the new drive immediately.

Expand the adjacent drive

The other approach, which in previous versions of Windows required third-party tools, is to simply expand an adjacent volume to use the unallocated space.

In our example, we’ll right-click the C: drive, and click Extend Volume…
Extend Volume option on C: drive
That option should only be available if there’s room to expand – meaning that there’s an unallocated partition following the C: partition.

This time, we’ll start the “Extend Volume Wizard”. Clicking Next takes you to the “Select Disks” dialog:
Extend Volume section dialog
This somewhat confusing step is all about selecting which partitions on the disk are to be added to the volume that we’re extending. The good news is that in this simple and common case – an unallocated partition immediately following the C: drive – the dialog is pre-loaded with default choices that are probably what you want: extend into the entire unallocated partition.

So all we need do is click Next.

A summary screen confirming our choice appears. Click Finish, and Windows begins the operation.

When complete, the unallocated partition is gone and the C: partition is larger:
C: partition extended to encompass the entire drive

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54 comments on “How do I use an “unallocated space” partition in Windows 7?”

  1. the problem is that some disk types max out and won’t let you use the unallocated space.

    I am trying to figure out how to overcome the 2TB restriction on System Active Primary Partitions. I removed windows from it but it still won’t extend.

  2. I have a partition labeled Healthy, Primary Partition with 12 GB showing use is 0%. Right click only give on active menu item — Delete Volume. What is that partition and is that 12 GB really unused?

    It probably is exactly what it looks like – an unused empty partition. My guess is that you’re not running Windows 7 since the menu shows no partition management options. (Or perhaps it’s a partition that Windows 7 can’t manage for some reason.)


  3. Works fine for most computers. But a new Laptop sometimes refuses to create a new simple volume saying that the maximum number has been reached. The machine suggests you craete a dynamic volume instead. A user like me ( a non-techie) does not know what this means and what it would do. This possibility remains unanswered by you and I look forward very anxiously for a solution.

  4. I’m still using XP Pro until I HAVE to go to Win7.
    Any advise?

    For Windows? Only that Windows 7 isn’t that bad once you give it a chance. For partition management? Easus partition manager.


  5. @Snert: buy a commercial product like Partition Magic (Shareware, not free) or look for a free product at your own risk.

  6. Re comment by dr d b karron at August 9, 2011 8:17 AM. I have the same problem and I have Win 7 64 bit and hav this section on my 2nd internal hard drive which has two partitions plus the healthy primary partition which I can’t I can’t do anythng with except Delete Volume and I don’t know what would happen if I deleted the volume. Would it just affect that healthy primary partition or would it affect all partitions on that drive?

  7. I have 410Gb of “Free Space connected with my Healthy Boot partition (i.e., the “C” drive). Whenever I tell disk manager to create a new volume out of this space, it walks me through the steps and then tells me there’s not enough space to perform this action (I’ve tried using he max indicated amount of space and several smaller allocations and get the same result every time). Any idea why I can’t use this “Free Space”?

  8. i had partition the system hardisk, which has the 450Gb. while partitioning the drive which shows like you cann`t create a new volume in this unallocated space because the disk already contains the maximum number of partitions..

  9. Hi, Leo!

    Your article about the unallocated disk space is really great. it’s easy to follow. Here’s my problem… I followed exactly the first way. but in the end my laptop said this, “The operation you selected will convert the basic disk into a dynamic disk. If you convert the disk to dynamic, you will not be able to start installed operating systems from any volume on the disk (except the current boot volume). Are you sure you want to continue? YES/NO”

    I clicked yes. It returned another message that said, “Dynamic disks are not supported by this operating system or server configuration. Dynamic disks are not supported on clusters. YES”

    I just clicked yes.

    In the end, I still have the 149 GB unallocated. I just want to use this because i am running out of space in my C. I hope you can help me further on this.

    thanks in advance.

  10. By the way, Leo… I also tried the 2nd way you stated in this article. Unfortunately, when i right-click the C to expand its volume (hoping that the unallocated could be transferred in C), the ‘extend volume’ and ‘delete volume’ are unclickable. Only the ‘shrink volume’ is clickable. Oh please, please help me. Thanks.

  11. You mean, when my computer was telling me I didn’t have any more room on my C drive, I could have extended it by reallocating one of the other allocated drives?

  12. Hi
    You told us how to creat a primary partition out of an unallocated partition
    My question is taht how can we create three new logical partition out of the unallocated space ?

    Simply select a size smaller than “everything” when creating the partition, and then repeat the process with the leftover free space.

  13. Hey “rodjoju”, I am facing the same problem as you did.

    “The operation you selected will convert the basic disk into a dynamic disk. If you convert the disk to dynamic, you will not be able to start installed operating systems from any volume on the disk (except the current boot volume). Are you sure you want to continue? YES/NO” ……

    Any solution to this? please keep me informed, urgent

  14. i am facing the same problem as rodjoju and sandeep that the basic disk will be converted to dynamic disk. please help as i have no clue about what to do further and i m having 212 gb of unallocated disk space..

  15. So, one of my disks is set up basically the exact same as your example (Sys. Reserved; Drive; Unallocated Space. Only difference is it’s 3TB) but both my “Extend Volume” and “New Simple Volume” buttons are greyed out.
    Now I’m missing out on ~750 GB of space, and it’s a little frustrating.

    Running Win7 64 bit, hardware inside is top-of-the-line (Or damn close), all updates have been done, no viruses / spyware. (Hardly any -ware at all, it’s a fresh system.)

  16. re.) the warning in Win7 : “The operation you selected will convert the basic disk into a dynamic disk. If you convert the disk to dynamic, you will not be able to start installed operating systems from any volume on the disk (except the current boot volume). Are you sure you want to continue? …

    If you are trying to recover space to reformat an entire drive as one partition and run into this problem, you might try this…

    In Disk Management, first
    -Create a new Simple Volume in the Unallocated Space.
    -Keep the new Volume and Delete the Old Volume .
    – Extend the new Volume into the Unallocated Space

    Done! :~)

  17. My d: drive is my hp recovery disk. update my recovery because my recovery is very old and some missing updates. but my d: drive is delete then i create new d: drive. then i will try to create recovery disk but system shows error ” a set of recovery disc has been created for this pc. only one set is allowed per pc. please help

  18. My BIG question is “What happen’s if I click Yes after the message: “The operation you selected will convert the selected basic disk(s) to dynamic, you will not be able to start installed operating systems from any volume on the disk(s) (except the current boot volume). Are you sure you want to continue? Yes / No” ???

    Will I then Not be able to boot windows on my PC?

    Note: All I want to do is add the 465GB of “Unallocated space” to a usable partician.

  19. Hey Leo im from Philippines.

    my 1TB HDD has 3 main partitions (not including system reserved partitions)

    C: is my windows (290 GB)
    E: is my my movies/song etc. (512 GB)
    i have Unallocated partition (110GB)

    since unallocated partitions cannot be merged to NTFS partitions, i have used the unallocated paritition to create a new partition called F: which is now 110 GB.

    while the merging process is about to complete, i get an error saying:
    “Not enough unallocated space before and after the selected partition for the move/resize feature.

    btw, im using EaseUS partition manager. can you help me with this?

  20. Hi Leo,

    Thanks for putting up this.

    I have an IOMEGA 500GB external drive, only around 1 year old and not frequently used.

    Recently I did some back up of my files. When thats done, I kept the drive. When I plugged in again, the drive is no longer accessible from My Computer. I am using Windows 8 Desktop environment.

    I did a google search and found that I have to select a drive letter. However, I left click, right click, still dun have the option to do that.

    In my Safely Remove Hardware icon, I can see “Eject IOMEGA HDD”. That means my drive not spoilt right?

    I have since followed your advice on creating a new Simple volume, but i did not format the drive as it contains important data. Now that I have the J: back, i cannot access anything inside it unless i format it and lose all my data? What can i do to get back the data?

    Thanks a million.!

  21. Hi Leo,
    I am using sony laptop. I have windows 7 and windows server 2008 r2 installed in dual boot. so i now I have 2 os partitions and a recovery partition. Now I want to shrink server 2008 partition(98gb), bcz i need a small partition to work on server. Till shrinking the volume, it is working fine but when I tried to create new volume on unallowcated space, its showing an error says “The operation you selected will convert the selected basic disk(s) to dynamic, you will not be able to start installed operating systems from any volume on the disk(s) (except the current boot volume). Are you sure you want to continue? Yes / No” ???
    so i dont want to loose the other operating system and yet want to create a partition.
    Could you please help me with solving the error…..thank you in advance.

  22. Thanks! Worked a treat. I replaced a failed 32GB SSD with a 250GB SSD but system was only showing 30GB after installing system image. Checked in Disk Management and the rest was showing as unallocated space, so did the ‘extend C partition’ thing and it did the trick – now have the full volume available in C. Thanks very much for this very helpful article.

  23. when I create new volume can I recover previous all data.I want not format local disk by creating new volume. how to do this please sent massages on my {email address removed}

  24. Best explanation yet, because I was afraid to click ‘Finish’ until I was sure it wasn’t going to do something unexpected. But, I want to do a Move, so I have to expand on one side, then shrink on the other.
    I was hoping to see a few words about ‘Shrink’ — or a link to that information — did I miss it, or maybe it could be added? I’ll do a search of Leo’s entire site, just to make sure.

  25. I have installed win 7 and format for another drive it show unallocated space for 64GB, i have create or format the disk the below message is came” the operation is not enough space to completed” my hard disk 64GB is unused what i can do.

  26. When I am creating new partition with unallocated space below error message is prompting. so kindly help me out from this error
    “Error already have the maximum number of partitions, unable to recover unallocated disk space”

    other than complete system format solution

  27. I have something related, but the volume is shown as Free space in green label I can only male a new partition on it, (i cannot convert it into unallocated space and use it for another partition, i have a 1TB Harddrive having about five partitions incl.this one ) please help me retribe my space.

  28. Your advice on extending a volume C into a following unallocated partition is very clear. My set up is that the unallocated partition is BEFORE (to the left of) the C partition. (I had just XP but made a Win 7 dual boot and this is how the disk was arranged – D for XP, Unallocated, then C). How should I extend in this case? (Does extend = merge?)

    Thanks for advice,

    • You’ll likely need to use a different tool – probably something like Easeus Partition Manager. That’ll let you move things around so that they’re lined up appropriately for combining. Windows built-in manager is somewhat limited.

  29. hai leo,
    I just followed your instructions regarding “how to make use of the unallocated space” but after I am done with the procedure starting from right clicking the unallocated space and then create new volume etc… at last a message appears which says
    ” this is not possible because some of your disks are basic and doing so will convert them into dynamic”

  30. Hey Leo…..very useful suggestions up there…..i have a 16 gb sandisk pendrive which has 14.6 gb unallocated space.
    BUT when i the option to create a new simple volume on it is whited out…..please help
    Also,i have four partitions on my main hdd..

  31. My options are grayed out. I have a 5tb drive that windows automatically split into 2tb and a 2.6 tb partions. I installed a fresh copy of windows 7 onto the first partition, and now when i am all done and booted up, the unallocated space has grayed out options. No idea how to make it into a normal data partition. Please help!

  32. I have a 3 TB drive which is partitioned into a 2 TB and a 1 TB spaces. The 2 TB partition is a “healthy” partition but the 1 TB partition does NOT give me the option to create a “new simple volume”. Create a new simple volume is faded out. What did I do wrong??

  33. I had partitioned my 500 GB hard drive into 3 Partitions:
    i) Windows XP with SP3 — because many of my existing software apps do not run on Vista, especially Windows 7 and above.
    ii) Windows Vista — just in case one of the OSs fails to boot, and there is need to recover important documents in that Drive by booting up another OS (in the other Drive).
    iii) Windows 7 — for certain websites that need IE8 and above.
    Firstly, I upgraded (changed) my Intel Motherboard — the new Desktop Board supports mainly SATA Drives (unless IDE to SATA Converter is added).
    Secondly, my Windows XP SP3 developed boot-up problems, but it could not be repaired with the existing Windows XP CD which is not slip-streamed with SP3 — nor does it have SATA Drivers.
    Thirdly, I could still access the Documents on this Drive (XP OS) through the other Drives. Suddenly the Master File Table and its “mirror” (MFT) became corrupt — it could not be repaired by CHKDSK.
    So, I reformatted that drive. And also deleted it — it is now being shown as “free space”.
    I tried to format that Partition with New Simple Volume Wizard and followed all the Steps onscreen but finally an Error window popped up with the following Error:
    “There is not enough space available on the disk(s) to complete this operation” .
    Then I tried to install Windows 8 in that Partition (Drive) but it failed to format the said Partition.
    Kindly suggest a solution, asap. Thanks in advance!

  34. Hi dear Leo,some of my drives on Win10 has been unloacated and thay’ve got about 500Gs data.Now how can I get my data whout format and recovery?
    Best wishes

  35. Thank you SOOO much. Not only was this very simple to follow, it immediately gave me “back” that unallocated space that I thought was lost. That unallocated space was due to following a YouTube video on how to “How To Make A Partition on Windows 7”. Problem is….it depends on which version of Win7 you have! Bc my 64 bit, Professional would have created Dynamic partition. THANKS AGAIN!!

  36. I’m using Windows 7 and have a 1 terabyte drive which I have partitioned in to C and D. D is strictly for data. I’ve just reformatted my C drive and made it smaller and this had left me with 50 GB of unallocated disk space which I’d like to add to my D drive to extend it. The instructions above for EXPANDING ADJACENT DRIVE doesn’t work in this case. When I right click on the D drive, EXTEND VOLUME is not highlighted as an option.

    I’m sure there is a way to extend my D drive. I’m just wondering if there is a way to do it that does not involved installing software … or installing only a portable tool.

    Would Acronis True Image bootable disk work for this?


  37. Hello again,

    Solved the problem in about 30 seconds using AOMEI Disk Partition Assistant Standard Edition which is free. It does require installation, but it’s a tiny file and doesn’t take up much space.

    Here is a YouTube video link on how to use it:
    Most important part on video is 1:40 –> 3:22

    • Using the Disk Manager or a program like EaseUS Partition Master, the process generally takes seconds.

  38. Great info because I used an HP tool that created a partition and didn’t know how to return to C: as every gb counted on 80 gb ssd.. Many thanks Don


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