Partitioning is a process of dividing mass storage like hard disk into isolated sections to store data. The partition is basically the framework of everything on your hard drive. Deleting partition will spare more unused partition space for other usage or re-arrange hard disk. However, you can't delete partition, if your hard disk is currently set up as a single partition. You also can't delete the system partition, boot partition, or any partition that contains the virtual memory paging file, because Windows needs this information to start correctly.
If you inadvertently deleted the wrong partition that has not been backed up, you can't access to the files on this partition. However, don't worry; you don't delete initially everything but just the parameters that mark how the partition is setup. You are able to recover deleted partition by reestablishing those parameters.
To do so, you need to utilize a third-party program. Deleted Partition Recovery is a piece of reliable software that enables you to recover deleted partition, as well as the partition that is formatted, damaged, or corrupted, and get back the media files that you accidently deleted. It supports media devices like hard drive, USB, memory card, flash drive, SD card, and etc. For Mac users, you can use Deleted Partition Recovery for Mac to recover deleted volume (the terms partition and volume are often used interchangeably).
The guide is broken into four steps and will walk you through every part of the clean partition undelete process.
Run Deleted Partition Recovery and enter to the main interface, and select "Partition Recovery". You can choose the computer's hard drive or the external hard drive if you want to recover the deleted partition from an external hard drive. Then click "Scan" to start scanning.
After scanning the lost partitions, all the recoverable partitions will be displayed. You can distinguish the partition you need by size. After choosing the partition, and hit on "Next" to get back all the data on this partition.
Then all the lost files on this partition are found. You can select the files you need to recover and click "Recover" to proceed.