通过注册表查看已安装 .NetFramework 版本

gci "hklm:SOFTWAREMicrosoftNET Framework SetupNDP" | % {(Get-ItemProperty registry::$_).PSChildName}

gci "registry::HKEY_LOCAL_MACHINESOFTWAREMicrosoftNET Framework SetupNDP"| % {Get-ItemProperty registry::$_} |Select @{Name="Version";Expression={$_.PSChildName}}

http://msdn.microsoft.com/zh-cn/library/hh925568(v=vs.110).aspx