Starting with Vista and 7, Microsoft Windows has a new feature that allows you to shrink (or decrease) the sizes of a primary partition and logical drives. For example, this is a good alternative when you are in a situation where you need an additional partition and you lack of extra disks. When you shrink a volume you free up space in the disk; this unallocated space can then be used to create other needed partitions.
Today we are going learn how to shrink a basic volume or partition using Windows graphical user interface and, for those who are more technical, we are also going to be using the command line method.
Before you begin, make sure that you backup all your important data, in the case that something goes wrong. If you don’t know how, we got you covered!
Shrink volume or partition with Disk Management
1. Go to Start , type “Computer Management” and press Enter.
2. In Computer Management, go to Storage and select Disk Management.
3. Now, Disk Management is the place where you will find all disks storage connected in your computer (Hard Drive, USB drive, CD/DVD, etc.) Select the primary partition you want to shrink, right-click on it and select Shrink Volume…
Now Windows is going to calculate the space available for shrinking.
4. Next, enter the amount of space that you would like to reclaim and hit Shrink. This can be a little confusing, but is not that difficult. The amount of space that you are entering is the amount of space that you are freeing up from the volume (or partition), the rest as you can see in Total size after shrink in MB,will be the new size, in this case for the Windows partition. Note, if you are modifying Windows partition, make sure you leave sufficient space in Windows partition for future program installations. One other thing to remember is that you need to enter the amount of space in mega bytes and to give you an idea: 1GB is equal to 1024MB.
With the free or unallocated space, you now can create a new partition.
Shrink volume or partition with command prompt
1. Open the command prompt, go to Start , type “cmd”, from the search result, right-click cmd.exe and select Run as administrator.
2. Type diskpart and press Enter.
3. In the DISKPART prompt, type list volume, this command will give you a list of all the disks in your computer. Make note of the one you want to shrink.
4. Now type select volume “and-the-volume-number-of-the-volume-you-want-to-shrink”, for example select volume 1 and press Enter.
5. Type shrink querymax, this command allows Windows to calculate what is the maximum amount of space that can shrink. Remember that the number of reclaimable is in MB.
6. You now have 2 options: The first one is to just type shrink and Windows will shrink the partition or volume to its maximum space reclaimable, or the second option which is to type shrink desired=1024 (this is an example where it says desired=1024, you can use any number you need, that do not surpasses the maximum space reclaimable) with this command you can specify the exact amount of space you want to shrink and then press Enter.
If you did everything right, after the operation is finished, you will see an out put that should say:
DiskPart successfully shrunk the volume by: 1GB
7. You done it! To leave properly DISKPART type exit and press Enter.
Things to consider for either methods
When you try to shrink a primary partition or a logical drive, you cannot decrease the partition size beyond the point where there are unmovable files (i.e., shadow copy storage area, hibernation, paging files, etc.). Put it this way, if in partition A, you have Windows, some “first” empty space, then some unmovable files, and some “second” empty space; you only are going to be able to shrink until the end of the second empty space, because of the unmovable files that are in the middle.
If there is a big number of bad clusters detected, shrink will fail.
You can use shrink in primary partitions and logical drives or partitions using NTFS file system, NO FAT16 or FAT32 or any other type of file system.
This should work in Windows 7 and Windows Vista as well.