環境

Oracle VirtualBox 5.2.6 r120293
Vagrant 2.0.1

`vagrant up` すると、 "Code E_FAIL (0x80004005)" ってなる

C:\Users\ndxbn\vagrantfile>vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'laravel/homestead' is up to date...
==> default: A newer version of the box 'laravel/homestead' is available! You currently
==> default: have version '4.0.0'. The latest is version '5.0.1'. Run
==> default: `vagrant box update` to update.
==> default: Clearing any previously set forwarded ports...
There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: ["modifyvm", "732261da-6e5f-4d2c-b776-2d8853c51d78", "--natpf1", "delete", "ssh", "--natpf1", "delete", "tcp27017", "--natpf1", "delete", "tcp33060", "--natpf1", "delete", "tcp44300", "--natpf1", "delete", "tcp54320", "--natpf1", "delete", "tcp8000", "--natpf1", "delete", "tcp8025"]

Stderr: VBoxManage.exe: error: Code E_FAIL (0x80004005) - Unspecified error (extended info not available)
VBoxManage.exe: error: Context: "LockMachine(a->session, LockType_Write)" at line 523 of file VBoxManageModifyVM.cpp

vagrant status やっても、default poweroff (virtualbox) と言われるはず。

VirutalBox マネージャーでみても、「電源オフ」になってると思います。

原因と対処法

たぶん、管理者権限で同じ名前のマシンが起動されている状態 だと思います。

cmd.exe を管理者として実行し、 vagrant global-status とかやると、同じ名前のやつが動いているのが見えると思います。