在下载安装boot2docker后，运行boot2docker init -v 返回错误：

/05/29 14:20:19 executing: C:\Program Files\Oracle\VirtualBox\VBoxManage.exe list hostonlyifs
/05/29 14:20:19 executing: C:\Program Files\Oracle\VirtualBox\VBoxManage.exe list dhcpservers
/05/29 14:20:19 executing: C:\Program Files\Oracle\VirtualBox\VBoxManage.exe hostonlyif create
%...
Progress state: E_FAIL
VBoxManage.exe: error: Failed to create the host-only adapter
VBoxManage.exe: error: Code E_FAIL (0x80004005) - Unspecified error (extended info not available)
VBoxManage.exe: error: Context: "int __cdecl handleCreate(struct HandlerArg *,int,int *)" at line 66 of file VBoxManageHostonly.cpp
error in run: Failed to initialize machine "boot2docker-vm": exit status 1