Step1. Launch Partition Assistant. Right-click the partition which you want to merge, select "Merge Partitions".
Step2. In the pop-up window, tick F: in the checkbox. And then click "OK" to finish.
Step3. Perform pending operations by clicking "Apply" on the toolbar.
Step1. Right-click C drive and select "Merge Partitions"
Step2. In the pop-up window, tick the checkbox of unallocated space, and then click "OK" to finish.
Step3. Click “Apply” on the toolbar to execute pending operations.