1. The main partition is low on disk space but other partitions have more disk space, so you want to merge those partitions and increase the free space on your main partition.
2. You may want to get rid of your partitions altogether and create a single partition.
No matter what your problem, if you want to merge partitions, you can achieve it by using Qiling Partition Master.
Qiling Partition Master Free is the first free partition software that offers Windows Home users a free "merge partition function" for up to two partitions. Windows XP/Vista/7/8/10 only.
This is an example to merge partitions, please follow the steps below:
Step 1: Select the target partition
Click on the partition which you want to add space to and keep, and select "Move/resize".
Step 2: Drag the system partition end into the unallocated space
Simply Drag the target partition end into the unallocated space so to add it to the target partition and click "Proceed" to start resize the partition.
Step 3: Select a neighbor partition to sync
Click "File sync" feature from "Backup and recovery" page, select one partition next to the former selected partition to continue.
Step 4: Select target partition for sync location to merge partitions
Step 5: Delete the no used partition