There is a common issue on Windows to have a disk blocked from Windows recovery partition. In that way, if you extend the physical disk (virtual environments) you cannot extend from Operating system side.
A recovery partition is a partition on the disk that helps to restore the factory settings of the OS (operating system) if there is some kind of system failure. This partition has no drive letter, and you can use only Help in Disk Management. In my case I did not need this partition and I was able to delete it with the below steps:
select disk 0 select volume 3 (3 was the id of my recovery partition)
delete volume ovveride
After those steps you will be able to extend your disk.
