Unlike Primary partitions that work as an independent unit, Logical drives are still part of the Extended partition, therefore, after deleting a Logical drive, the disk space will be shown as Free instead of Unallocated.
Better than Windows XP, Windows 7 has built-in Extend Volume function in Disk Management, which can be use to extend partition without losing data. However, due to some inherent limitations, you cannot extend primary partition with Disk Management in some situations.
A 250GB hard disk cannot be increased to 300GB, so before extending a drive you must delete or shrink another drive. Extend Volume can only merge Unallocated space to the left contiguous partition, but Shrink Volume function can only make Unallocated space on the right side, so when you right click C drive after shrinking D, Extend Volume is disabled.
Cannot get contiguous Unallocated space to enable Extend Volume, some people try to delete the right contiguous partition. It works if both partitions are Primary, but if the partition that you want to delete is Logical (such as E:), you cannot extend the Primary partition (such as D:) after deleting.
As you see in the screenshot of my Windows 7 Disk Management, disk space of drive E: shows as Free after deleting, Extend Volume is grayed out for drive D.
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.
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.
Comparing with Windows Disk Management, NIUBI Partition Editor is much more powerful.
Comparing with other disk partition software, NIUBI also has advantages such as:
Download NIUBI Partition Editor, you'll see the main window with disk partition structure and other information.
How to resize and extend Primary partition in Windows 7 (32/64 bit):
Step 1: right click drive D and select "Resize/Move Volume", in the pop-up window, drag left border towards right or enter an amount in Unallocated space before.
Step 2: right click drive C and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.
Step 3: click Apply on top left to execute. (All operations before this step only work in virtual mode.)
Watch the video how to shrink and extend partitions:
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 back up and run the reliable software. As the safest tool, NIUBI Partition Editor help you resize/extend both primary and logical partitions fast and easily.