How to enlarge the Virtual Machine (Window System) hard disk in VirtualBox

One: Environment Introduction I installed a virtual machine (win7 system) in Oracle VirtualBox, only assigned a 10G dynamic allocation storage hard disk for the virtual machine, there is only a C disk in the virtual machine, and there is not enough space. Want to enlarge the C disk.
Two: Operation Step 2.1 expansion VirtualBox virtual hard disk
#先关闭虚拟机 #切换至vboxmanage命令所在的目录, such as:
#扩容
--resize: That is, the size of the adjusted disk space, in megabytes. #检查下virtualbox里该虚拟硬盘是否扩容成功

2.2 Expansion of Virtual machine disk
At this point, the C disk found in Windows did not increase (I am now only 400MB of C disk, and then copy a 1G file to C disk, suggesting insufficient space. Right-click ' Computer '-' manage '-' storage '-' Disk Management ' and found that 15G unallocated hard drive is added:
Right-click C Disk-' Extend Volume ':
After the expansion, refresh, see the C disk added around 14G.