Case 1: There is not unallocated space adjacent to the 'insufficient room' partition C. However, in most cases, there is no unallocated space on the disk or it is not adjacent to the drive C:, these videos show you how to extend drive C in different cases.

Using gparted delete the un-needed partition and move the FAT32 partition to the end of the disk. The unallocated space must be next to the drive C: if you want to extend a drive C: directly.

Choose not to convert the disk to a later format if asked.

With the Linux VM shutdown add an existing disk and point it at the Windows 10 Pro Disk.

In VMWare Workstation (or this could be virtualbox too) create a Ubuntu/Fedora Virtual Machine or run a live CD in a VM and install gparted.

You need contiguous space to extend the drive Resolution Steps

Windows 10 Pro installed itself with a FAT32 EFI partition at the end of C: and I can’t extend the disk in VMWare Workstation and then extend C: using windows tools.

and I had extended the drive and created a 40GB but found that because of the FAT32 100MB partition I couldn’t right click and extend the C: drive.

579MB System Reserved (recovery partition).

My Windows 10 Pro VM had a disk comprising When attempting to extend the C: drive the Windows disk manager extend option is greyed out Cannot extend the C: Drive of my Windows 10 Pro VMWare Virtual Machine.

How to extend c partition