You can repartition drive C before reinstalling the system. Make USB disk startup disk with Xiaobai one-key reinstallation system tool. Then insert the startup disk into the computer and press the startup hotkey to select the startup item of the U disk to enter the pe system.

In the pe system, pay attention to backing up your own disk data, then open the diskgenius partition tool, delete the original old partition and re-partition.

Save the partition, and then open the Xiaobai installation tool to install the system.