Windows 7 不能自动给移动硬盘分配盘符 | Windows 7 won't assign a volume letter for removable hard disks automatically

症状:
插上移动硬盘后，显示连接了usb设备，但是在我的电脑里看不到新盘符。
用计算机管理里面的磁盘管理可以手动设置盘符，然后可以使用。

解法：
以管理员权限运行命令mountvol /e

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Symptom:
A new volume won't appear in 'my computer' after plugging in a removable hard disk, but it shows that a new usb device has been plugged in.
A volume letter can be manually assigned through the disk management in computer management console, then the removable disk can be used normally.

Solution:
run as adin: mountvol /e