Primary partition

Resize/extend Primary partition on Windows 7

C drive full is the most common issue in Windows 7 both 32 and 64 bit. Windows 7 has been released for such a long time, so many people added or replaced disk with SSD (solid-state drive) when updating computers. It is good to improve performance, but more likely running out of disk space, because SSD is much smaller than traditional mechanical hard disk. Luckily, your can re-size partition and extend the drive that is running low, no matter you use SSD or mechanical disk.

Unlike GPT disk that can only create primary partitions, there could be Primary partition, Logical partition and Extended partition in MBR style disk. You may encounter many trouble when you resizing disk drives if you do no know about the difference. In this article, I’ll show you how to resize and extend primary partition on Windows 7 without losing data.

What is Primary partition?

As a storage unit of a hard disk, Primary partition has no difference with Logical partition in daily usage, you can save, copy, paste and delete files without any issue. Then why there are both different types of partitions in Windows 7? It is related to file organization strategy. In MBR disk, there are maximum 4 entries in Master Boot Record area, from which Operating System can locate the positions of the partitions. What to do if you create more than 4 partitions in a disk? The last entry is converted for Extended partition, when you create a new partition, the entry is added in another area.

Primary partition

There are only 4 entries in Master Boot Record area, this is the reason why you can only create 4 Primary partitions, or 3 primary partitions plus an Extended partition in an MBR hard disk. Extended partition works like a container, new partitions are created as Logical in it.


  1. Only Primary partition can be set as Active to boot Windows.
  2. If you cannot create new drive because there are already 4 primary partitions, you can convert one of it to Logical without losing data with NIUBI Partition Editor.

Limitation to extend Primary partition in DM

Better than Windows XP, Windows 7 has built-in Extend Volume functionality in Disk Management, which can be use to extend both primary and logical partition. However, due to some inherent limitations, you cannot extend primary partition in some situations.

Limit 1: There must be right adjacent Unallocated space

A 250GB hard disk cannot be increased to 300GB, so before extending a drive you must delete or shrink another drive. Shrink Volume functionality can help decrease a drive, but the Unallocated space can only be produced on the right side, so when you right click C drive, Extend Volume is disabled after shrinking D.

Extend volume disabled

Limit 2: Space in Logical partition cannot be extended to Primary partition

Programs are installed to drive D, so you cannot delete it to get adjacent Unallocated space and enable Extend Volume for C drive. But to data drive, you can transfer files and delete it. However, if this data drive is a Logical partition, you cannot extend other primary partition even if you delete it.

Extend primary partition

As you see in the screenshot of my Windows 7 Disk Management, Extend Volume is grayed out when right click drive D. Different with Primary partition, Logical drive will be converted to Free space after deleting.

Limit 3: FAT32 partition cannot be extended

Actually, both Shrink and Extend Volume only support NTFS partition, FAT32 and other types of partitions cannot be shrank or extended under Windows 7 Disk Management.

FAT32 primary partition

As you see, there is adjacent Unallocated space on the right side of D, but Extend Volume is still inactive, because the primary partition D is formatted as FAT32.

Resize Primary partition with software

Comparing with Windows 7 native Disk Management, professional partition software is much more powerful. Both NTFS and FAT32 drives are supported to shrink and extend, to do this, you just need to drag and drop on the disk map. Better that other partitioning software, NIUBI Partition Editor is integrated with unique 1 Second Rollback technology to ensure system and data intact. Nobody likes to see system boot failure or data loss after resizing and extending the primary partitions.

Steps to extend primary partition on Windows 7:

Download NIUBI Partition Editor, you’ll see all disk with partition layout on the right side, which is similar with Windows Disk Management. Better than Disk Management, NIUBI can shrink a drive and produce Unallocated space on either side. It is also able to extend a drive with Unallocated space on either side.

I’ll show you how to shrink D and expand C drive, both are primary partition.

NIUBI Partition Editor

Step 1: Right click D and select Resize/Move Volume, drag left border rightwards to shrink D in the pop-up window.

Decrease D

Drive D is shrank and 20GB Unallocated space is produced on the left side.

Unallocated produced

Step 2: Right click drive C and select Resize/Move Volume again, drag the right border rightwards to combine the Unallocated space in the pop-up window:

Extend C drive

Primary partition C is extended to 50GB.

C drive increased

Tips: NIUBI PE works in virtual mode to prevent incorrect operations, click Apply on top left to take effect if you want to repartition hard disk like this.

If you still do not understand how to extend primary partition in Windows 7, watch the video guide.

In Summary

There is no difference in daily usage if you use primary or logical partition, but if you want to resize primary partition with Windows 7 Disk Management, there are many restrictions. The better method is running third party partitioning software, but because of potential data loss risk, you’d better select the safe and reliable tool. As the safest disk partition software, NIUBI Partition Editor help you resize/extend both primary and logical partitions fast and easily.

Download to try