You can use the two built-in tools in Windows: Disk Management and Diskpart. However, the two tools cannot delete all partitions at once. Use Disk Management: Step 1: Open Disk Management. Step 2: Right-click one of the partitions you want to delete, choose the Delete Volume feature, and click the Yes button to confirm. Step 3: Repeat the above step 2 to delete other existing partitions. Use Diskpart: Step 1: Open Diskpart. Step 2: Run the following commands one by one and repeat running the last two commands: select partition * and delete partition until all partitions are removed. list disk select disk * (* refers to the disk number) list partition select partition * (* refers to the partition number) delete partition There is another easier way to delete all partitions and it is detailed in How to Delete All Partitions with Ease in Windows 10/8/7.