To increase C: drive on Windows VM…MAKE SURE THE VM does not have any snapshots!!!
1. shutdown VM you want to grow
2. Edit settings on the VM, go to hard disk and increase it to the desired size.
3. At this point, the OS can "see" the unallocated space in disk manager; however the C: drive is still the same size. We need to grow the windows partition using diskpart.
4. Attach the disk (vmdk) that you just grew to another virtual machine with a like OS. Use the VI client to "add a hard disk" to the VM that you are using to extend the partition (select the "use an existing hard disk" option).
5. Do a "rescan" in windows disk manager on the VM you are using to temporarily attaching the drive to.
6. open a Windows command prompt and type diskpart
7. Show the volumes that are on the system: DISKPART> list volume
8. Select the volume that you want to grow: DISKPART> select volume n where "n" is the number of the volume you want to extend.
9. Verify you have selected the correct partition, there will be an asterisk next to it:
DISKPART> list volume
10. Extend the partition in diskpart: DISKPART> extend
11. Shutdown the VM that you are using to extend the partition
12. When the VM is shut down, remove the disk that was previously attached - choose the "remove from virtual machine" option.
13. You can now power the original VM back on.
14. you should now see the increased disk space; the server may ask you to reboot after it sees the partition increase.