Change Partition Size in Windows 10

Monday, March 27, 2017 by Jane

Windows 10 Disk management can help us to create more partitions when new hard drive always make whole disk as a C partition, but after months of using computer, some partition ran out of space, Extend Volume in Disk management greyed out because it found no unallocated space followed to active this function. Unless you can allocate free space from other partition full with free space we can see Extend Volume Wizard again.

Shrink Volume in Disk management to active Extend Volume option in other partition? Do you mean to Shrink D Volume, for example, so as to make Extend Volume in C Drive clickable again? No, that's not gonna happen, no matter how much you shrank, you won't active Extend Volume option, and it's not about the capacity but the position that matters.

It's OK to create space unallocated with the Function Shrink Volume, but the option of the unallocated space you created is not continues to C Drive but D Drive, that's why Extend Volume in the right-click menu of C Drive still greys out. Disk management doesn't have the ability to move unallocated space. So if you want to resize Windows 10 partition without data loss. Disk management is the last option when you made up your mind to do a backup for hours and spend more time to do the restore.

The theory of resizing partition and no touching data in Partition Expert is to move free space in Partition A to Partition B, no formatting partition, no backing up and restoring data in the background (that'll be very slow and that's not resize move at all), no damaging data to make a path to free space. It's just redistribute disk space (used space and free space) in a more scientific way… OK, Stop the princples! Just show me how to resize my Windows C Drive while my data stay intact:

1. Download Partition Expert, choose 32-bit or 64-bit to install and run (Note: you can directly run the portable edition after unzipped).

2. In the main interface find Resize Move Volume option, that's the main function we're gonna use when partitioning. Now, find a partition you wanna decrease and click on Resize Move Volume to continue.

Resize Move Volume in Partition Expert

3. This resize partition window is divided into 3 sections, on top of which is the operation bar, in the middle of which is partition capacity info and we put mini-disk-map at the bottom of this window so that you can see real-time resizing effect. In the operation bar, we can drag the handle inwards to decrease partition. Just drag it and we'll go next.

4. In the main disk-map of the first window, unallocated space is created. If you dragged the left handle in the resize window, unallocated space is right next to C Drive; else it stays at the end of D Drive. If the unallocated space locates not at end of C Drive, use Resize Move Volume again to make it there.

Extend Volume in Partition Expert

5. If you click Commit Now and run Disk management, you'll find Extend Volume of C Drive is now active, you can follow the Extend Volume Wizard and increase C Drive, or you can stay in Partition Expert to Resize C Drive and click Commit again. It's your choice.

We can of course use the built-in Disk Management to extend or shrink volume, to extend a volume, we need contiguous unallocated space available, to shrink a volume, the partition should not contain unmovable data

Extend Volume in Disk Management

Click on the search box in Windows 10, or just press enter and type Disk Management, alternatively, you can right-click on the start button and select it, if there’s unallocated space next to the drive you want to extend (I mean on the right, not the left), then do the following:

  1. Right-click on the target drive and choose Extend Volume
  2. Then the Extend Volume Wizard will come up, follow it to extend the volume

If by any chance, that option is greyed out, it mostly means that there’s no unallocated space on the disk, or at least, it’s not right next to the drive you desired to extend, since Disk Management can’t move partition, we have to delete the contiguous volume so as to make that space as unallocated again to active the greyed out option, but before you decide to delete any partition, check the Partition Expert methods instead.

Shrink Volume in Disk Management

This is an easy operation in Disk Management, just right-click on a partition and select Shrink Volume, then do the followings:

  1. When the Shrink Volume pops up, it will ask you to enter the amount of space to shrink in MB, just type the number and press enter to shrink
  2. Or directly click the Shrink button to use the suggested number

Wait for minutes for the volume to shrink, time spend on this mainly depends on the size and your computer speed.

Mine show error like this:

There's no enough space available on the disk(s) to complete this operation

The error doesn’t make any sense, because I have about 42% free space on the disk, I think it’s the unmovable files that cause the failure, so I tried our own software like so:

  1. Click on D Drive and choose Resize/Move Volume
  2. Drag the right side handle to left (or the left one to right) and click OK
  3. Then Click the Commit button in the main interface

And it worked, no error message, no need to delete or format the partition, no data loss.