奇怪了，之前在另外一台server上面还是可以用的，刚开始怀疑是不是PowerShell版本太低了，索性查一下：
PS C:\Users\admin> $PSVersionTable
Name Value
---- -----
PSVersion 5.1.14393.2515
PSEdition Desktop
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.14393.2515
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1 版本都5.1了，不是很老啊！OK，那再来看看有没有AD模块吧，毕竟这个命令是对AD的操作。运行： get-module -listavailable 回车，走你，结果一看。原来如此，目测没有AD模块。
那就导入一下吧，运行：
PS C:\Windows\system32> Add-WindowsFeature RSAT-AD-PowerShell
然后再运行一把get-module,看一下，ActiveDirectory加载过来了
PS C:\Windows\system32> get-module -listavailable
最后运行一下命令：PS C:\Windows\system32> Get-ADOrganizationalUnit，不再报错，而且提示需要参数，着就对了。
我在另外一个server上面也试了另外一种方法：
首先运行：get-module -listavailable 查看ActiveDirectory模块是否已经加载。
然后就是直接运行：import-module activedirectory
如果没有报错，就再运行：get-module -listavailable
这个时候ActiveDirectory模块就被导入了，关于AD相关的PowerShell命令你就可以开始用了。
The term ‘Get-ADOrganizationalUnit‘ is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:5 char:38
+ $SVSOUList = Get-ADOrganizationalUnit <<<< -SearchBase $sourceOU -Filter {Name -like "W2K8_*"} |select -ExpandProperty Name
+ CategoryInfo : ObjectNotFound: (Get-ADOrganizationalUnit:String) [], CommandNotFoundException
+ FullyQualifiedErrorId : CommandNotFoundException
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
PS C:\Users\admin> import-module activedirectory
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
PS C:\Users\admin> get-module -listavailable
ModuleType Name ExportedCommands
---------- ---- ----------------
Manifest ActiveDirectory {}
Manifest ADRMS {}
Manifest AppLocker {}
Manifest BestPractices {}
Manifest BitsTransfer {}
Manifest GroupPolicy {}
Manifest PSDiagnostics {}
Manifest ServerManager {}
Manifest TroubleshootingPack {}
Manifest Citrix.XenDesktop.Admin {}
Manifest Citrix.Common.Commands {}
Binary TelemetryModule {}
原文：http://blog.51cto.com/jiaszwx/2317941