How to manage your disks using only Windows Vista’s Disk Management tool

Some of our readers asked us how they can manage their disks in Windows Vista. To answer their questions we created this tutorial where you can learn the following: how to change a drive letter, how to shrink an existing partition, how to create a new partition, how to format or delete a partition and how to extend a partition.

Everything is done using only one tool called Disk Management. As you will see, things are pretty simple. Just follow our instructions and you will finish in no time.

Where to find the Disk Management tool

There are several ways to find the Disk Management tool. One is to search for the word “computer” in the Start Menu search box and click on the Computer Management shortcut.

Start Menu

Computer Management gives you access to several system management tools, including Disk Management.

Computer Management

Another way is to go to Run (Windows key + R) and type diskmgmt.msc. This command will open the Disk Management tool directly.


How to change a drive letter

First, select the partition for which you want to change the drive letter, right click on it and select Change Drive Letter and Paths from the right click menu.

Disk Management

Click on the Change button.

Disk Management

From the Assign the following drive letter drop down list, select the new driver letter you want to assign and click on OK.

Disk Management

You will receive a warning stating that some programs might not run correctly if you change the drive letter. If you did not install any applications on that drive it should be OK to change it. Click on Yes and the drive letter change will be done.

Disk Management

For some partitions you will not be able to change the drive letter. This happens with partitions where you have installed an operating system, partitions on which you have page (swap) files or where boot information is stored.

How to shrink an existing partition

Select the partition you want to shrink, right click on it and select Shrink Volume.

Disk Management

In the Shrink window you will see the total size of the partition and the maximum available shrink space in MB.

Disk Management

Type the amount of space you want to shrink (in megabytes) and then click on the Shrink button. The Disk Management tool will start shrinking the selected partition.

Disk Management

During this process you will see a rotating cursor. When finished, the rotating cursor will disappear and you will see the shrunk space appearing as unallocated space next to the partition which was shrunk.

Disk Management

How to create a new partition

To create a new partition you need to have some free, unallocated space. This can be obtained from shrinking an existing partition or by adding a new hard disk to your computer. Select the unallocated space, right click on it and select New Simple Volume.

Disk Management

The New Simple Volume Wizard will start. Click on Next.

Disk Management

In the second window of this wizard you will see the maximum available disk space. Select the size of the new partition (in megabytes) and click on Next.

Disk Management

Now you can assign a drive letter to the new partition. Select the letter you desire from the drop down list and click on Next.

Disk Management

In the next window you can choose whether you want to format the new partition or not. If you chose for now not to format the new volume, in order to use it, you will have to format it anyway later. If you choose the second option, you will have to select the desired file system and the allocation unit size. The default values (NTFS file system & default allocation unit size) are very good so there is no need to change them. You can also type the label of the new partition and select the quick format option.

If you just installed a new hard disk it is recommended that you perform a full format and not a quick one. In other cases the quick format is a good option.

When you are done setting all the needed options, click on Next.

Disk Management

The last window of the wizard will show you a summary of the changes that will be made. Quickly go through the summary and if you notice some incorrect settings press the Back button until you arrive to the appropriate wizard window and make the necessary changes. When you are done, click on Finish.

Disk Management

Depending on the options you have selected, the creation of the new partition will take from several seconds up to several minutes. When the process is completed, you will see the new partition listed in the Disk Management tool.

How to format a partition

Before formatting a partition, make sure you back up all the important data you have on it. Now, select the partition you want to format, right click on it and select Format.

Disk Management

Type the new volume label (in case you want to change it), choose the desired file system and the allocation unit size. When done making all the settings press on OK.

Disk Management

You will receive a warning that formatting this partition will erase all data on it. If you want to continue, click on OK.

Disk Management

The formatting will now start. You will see the process status in the square that represents the partition in the Disk Management tool.

Disk Management

How to delete a partition

Select the partition you want to delete, right click on it and then select Delete Volume.

Disk Management

You will receive a warning saying that deleting this volume will erase all data on it. If you want to continue, click on OK

Disk Management

The partition will be deleted and it will appear as unallocated space in the Disk Management tool.

How to extend a partition

You can also extend a partition by adding unallocated space that might be available. First, select the partition you want to extend, right click on it and select Extend Volume.

Disk Management

In the first window of the Extend Volume Wizard click on Next.

Disk Management

Select one of the disks that has some space available, type the amount of space you want to add (in megabytes) and then click on Next.

Disk Management

In the last window you will see a summary of your previous selections. Click on Finish and the selected partition will be extended.

Disk Management

NOTES: this tutorial was created with UAC turned off. If you have it turned on, you will have to make some additional confirmations for the changes you want to apply. You will not be able to successfully use Disk Management if your user is not an administrator.

Related articles:
Manage your drive letters in a dual-boot configuration
The 9 commandments for an enjoyable computing experience
How To Uninstall Windows Vista Using EasyBCD

36 thoughts on “How to manage your disks using only Windows Vista’s Disk Management tool”

  1. Extend Maximum? – Can’t Extend past 465.76GB

    I have a 1TB usable RAID 5 array as my “D” drive (Intel onboard ICH9R controller). But for some reason Vista will only allow “D” to be a maximum of 465.76GB. Its NTFS format. Disk Manager screen clearly shows I have 465.74GB unallocated to the right of the allocated partition for “D”, and the Extend Volume Wizard shows the total volume size of 953854MB as well. However, any time I enter a larger value, the “Next>” button the Extend Volume Wizard screen goes grey.

    I thought Vista allowed 4TB volumes?

    Does this have something to do with the cluster size I chose? [Can’t find it from this screen, but I believe I left it at the default size suggested when creating the volume.]


  2. formatting
    Unfortunatelly your guide is not usable in my case because even though the physical disk exists and is shown under Disk Management as two healthy unformatted partitions all the right-click options are greyed out and only “help” and “delete volume” are available. So I still do not know how to format existing HD.

  3. Partitioned external drive
    My external was partitioned in 4 parts and I wanted to change it to 2 parts. Following your tutorial I was able to easily accomplish this! Thanks!

  4. Re:Cannot make partition on unallocated shrink volume…
    I followed your guides on creating new partition.First I have 99 GB on my C: as per instructions on creating new partitions I shrink volume C: with 10 GB then right click the unallocated volume and followed the wizard and all instructions. After completing the wizard an error occurs saying there’s not enough space available on the disk to complete this operation????Whats wrong I still have 90 GB on my disk?

    How can I delete this unallocated volume? and sends it back to volume C:? I cannot erase the unallocated volume because when I right click the volume the only highlighted is new simple volume, properties and help?

    Need your help on this……..

    Thanks you in advance and looking forward for the help…..


  5. Computer / Disk Management

    I wanted to extend or increase the partition size of my D: drive so that I can do back up’s. As of right now I have no available space to do this and I need to start creating back up’s so that I can do an accurate restore of my computers data files.

    Peter Kern

  6. extending partition

    Is it possible to add another space allocated for my OS, i only partitioned it with 20GB, the problem is i have already reach the 19GB mark…? can I add the unused space of my hard disk to my OS partition?

  7. Formatting 250 GB USB HDD

    I have a 250 GB external USB HDD formatted in NTFS. I need to shrink the volume to create around a 30 GB FAT32 partition which is compatible with the xbox 360, and I currently have 72GB of free space on the drive. However when I go to shrink volume i can only shrink it by a maximum of 15.5 GB? Why can’t I shrink it by more?

  8. assigning drive letter
    Everytme I shutdown, my external hard drive loses its drive assignment and goes from E: to F:…. any help as to how I can keep the letter assigned? thanks very much

  9. regarding issue in formatting a new partition
    I havea primary partition of 225 gb in my laptop.i tried to shrink it into 2 partitions 80gb and the remaining in C only . i was successfully done with that .after sometime when i tried
    to format the unallocated space its giving me an error “there is not enough space available on the disk to complete this operation ”
    .Plz suggest me what could be the solution for it .

  10. disk partition
    I followed the above given steps for creating new partition in the C drive, but it did not work. C drive has 124 GB free and i shrunk it by 30 GB. After I click the ‘finish’ button of the new simple volume wizard, it shows an error message stating that ‘There is not enough space on the disk(s) to complete this operation’ . Any solutions for this problem?

    • RE: Disk Partition

      I am about to partition my C drive on my new computer and was wondering if they have provided you a solution for the “there is not enough space on the disk(s) to complete this operation”? I don’t want to run into this same problem if I was to partition my C drive.

      Thanks in advance.

  11. Dual platform portable hard disk for OS X and Windows.

    I bought a 250 GB portable hard disk and would like to make it dual platform since I am using both Windows and OS softwares.My desktop is Window Vista and notebook is a Mac. Tried to partition the hard disk to 32Gb (max for FAT 32) using Vista but not successful as the default in Vista is NTFS format. Could you advice? So how do I save my documents when I am using windows office for Mac and retrive them in Vista and XP or vice versa.

  12. XP/Vista Dual Boot Data Partition

    I just bought a laptop with Vista Home Premium installed. I’d like to divide the hard drive into three partitions: one for Vista, one for XP, and a third for data that could be accessed by either XP or Vista. I have already found out how to add XP and create a dual boot system, but I need to know about the data partition. Please help.


  13. Error while formating new partotion
    I have 250 GB HDD and ‘m shrink 50 gb , when i format that partion i got a error like ‘ You can not create a new volume in the unallocated space because the disk already contains the maximum number of partition ‘, but i have only one partion , and a dvd drive ….. how can i ……

  14. explanation why no more partitions are possible with Dell
    As I read in forums, that’s because Dell usually comes already with 4 partitions and you cannot have more (two of them do not have letters, that’s why you don’t see them).

  15. unallocated disk related
    i’ve problem with unallocated disk…
    i’ve 320gb hdd..
    i partitioned it & reinstalled vista..
    n i’ve 190gb unallocated..
    now i’m trying to allocate it but it says max. no of partiotions….when press finish to new drive..

    wt should i do??

  16. Partion Hdd for Dell inspiron 1525
    I am tried to partion the harddisk Vista operting sysem, an error message is showing ” there is not enough space available on the disk to continue this operation, how can solve this issue


  17. Need help
    I have two drives one was called “C” and the other “D” I have an accer laptop so the drives were split that way. Now what I wanted to do was merge C AND D together using disk management. It worked perfect but the next time i restarted my laptop Drive “C” had only around 10mb on it which was what drive “D” had last time I left it. I was bafled by this and know how to use disk management well. But what I dont understand is how my 102.02mb was moved from drive “C” onto a drive that has no name. I right click this drive and the only thing is says is “help” which is not helpful in the least. The drive that has taken my 102.02mb from disc “c” was located at the top of disc managment orginaly. I dont understand why I cant do anything with this drive. Everytime I click it, it only says help.

    Do you have any idea what may have happened? And help would be very much appriciated. Thanks in advance JJ.

  18. Adding more space to my “C” Drive
    I am trying to extend my “C” drive since I only have less than a Gig left and want to install Office. I cannot extend it using the above method. When I right-click it , the extend partition option is grayed out. Does anyone know how to do this using Disk Management? I even tried to use Gparted and cannot figure out how to add more space to me “C” drive without re-installing Windows and starting all over again with a fresh larger partition.
    Thanks for the help in anticipation!

  19. Access Denied during Shrink Volume
    I have Windows Vista 64-Bit Home Premium.

    I have an hard disk of 250GB.

    It has only one partition of 236GB as “C” Drive.

    If try to shrink the volume, it gives the error as access denied.

    Could you suggest me how solve this issue.

    Even i tried by disabling the UAC. But no use.

  20. I have 250 GB HDD and
    I have 250 GB HDD and shrinked 100 gb , when i format that partion i got a error like ‘ You can not create a new volume in the unallocated space because the disk already contains the maximum number of partition ‘, but i have only one partion. help please!
    I am using dell inspiron 1525

    • i had the same problem
      i had the same problem too.
      you should take the following actions:
      1. reboot
      2. delete it first “Delete ..” …becomes black
      3. than “Extend …” … and it works…it is automatically formated .

  21. one of partitions has 30.2gb
    one of partitions has 30.2gb totally and 12.3gb free space, i tried to shrink but it says 0 mb so i tried defragment it with vista’s defragmenter, auslogics disk defragment and JkDefrag-3.36 but same result 0mb
    i need about 7gb, i also deactivated page file and deleted pagefile.sys. what should i do?

  22. Shrink vista
    Is it possiple to shrink the only part af HDD which OS is on .I have notebook which vista run, I have only one partititon that is drive C .I can NOT shrink this part because of OS is on.How can I do this without formatting or re-setup the vista .

  23. drive letters
    after i changed the drive letters of the partitions on my second hard drive and rebooted it wasn’t recognized and i didn’t want to format it because i had data on it. i didn’t activate system restore on the 2nd hard drive

  24. Being new to this is tough.
    Being new to this is tough. I was not aware that you could use unused disk space. Seeing the process of how to use the unallocated space was interesting. I learned that by using this process you don’t have to go out and buy a new hard drive to get more space. Its interesting for me to see how all this works. I relate some of what I’m learning to how the IT Dept operates where I work. Seeing how much is involved in what they do makes me have more respect for them. Without them we could not function.

  25. Extending a drive by another drive space
    I want to extend my C drive by 10 GB using another drive free space on windows vista. Is it possible?
    I shrank my D drive some space to extend my C drive but it seems that I can only shrink one drive and extend only the same drive by that free space. Any solution? Can I use a drive space to extend another drive?

  26. shrinking c:
    hi , i’ve followed your instructions , but i have 150GB C , and 120 GB D ,

    i wanned to shrink some space from c and extend it to d , but C: doesn’t allow me shrinking more than 450mb ,although there are 120gb free, why ?
    and D: also doesnt want to extend any volume …
    please help …

  27. creat a new partition
    I have a 40GB harddisk. I installed the operating system in 40GB.
    I like to creat a new partition to keep my important to creat a new partition in this hard disk, i don’t like format the operating system. this is possible? if it possible how to creat?

    I wait for your reply…….


  28. My drive is missing
    Hi I have seen your way of explaining how to manage disk management. But I have got new problem with my computer please give good suggestion how to resolve my problem.
    Normally I have 3 partitions but unfortunately one of my drive is missing while I open computer folder. still the 3 drives is in disk management and when I click on that drive which is missing options is not enable to get (open or explore etc). please let me know how to get resolve my problem with out loosing data and how to get back my drive active please.

  29. disk management external HD

    I am experiencing problems as I try to extend O: 65GB to use all the unallocated space (9.77 GB) on my Disk 2.
    Disk 2 also has dr M: @ 35GB.

    My problem is the error message as seen on:
    I then made a Simple Volume and tried to extend O: but “extend” was grayed out and not offered.

    I do not know what to do in Win and before I try to use cmd prompt I wanted to ask for advice.
    I assume if I have to use cmd I will extend and the unallocated space will automatically be used up, correct?

    The PC Magazine Vista book I have offers no help.

    Any help is appreciated.
    Regards, Mark..

  30. cannot crete a new volume in vista
    i have following partitions:
    c: 102.23gb healthy (windows vista)
    d: 53.67gb healthy (logical derive)
    e: 9.9gb healthy (HP_RECOVERY)
    s: 49.71gb healthy (primary partition)

    10.29gb (free space)green color,left side of d: drive
    7.07gb (unallocated space)black color ,right side of d: drive
    when i want to create a new volume of these two free space the following error occurs :
    there is not enough space available on the disk(s) to complete this operation

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