Get-DotNetFrameworkVersion.ps1

function Get-DotNetFrameworkVersion
{
    param(
        [string]$ComputerName = $env:COMPUTERNAME
    )

    $dotNetRegistry  = 'SOFTWARE\Microsoft\NET Framework Setup\NDP'
    $dotNet4Registry = 'SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full'
    $dotNet4Builds = @{
        '30319'  = @{ Version = [System.Version]'4.0'                                                     }
        '378389' = @{ Version = [System.Version]'4.5'                                                     }
        '378675' = @{ Version = [System.Version]'4.5.1'   ; Comment = '(8.1/2012R2)'                      }
        '378758' = @{ Version = [System.Version]'4.5.1'   ; Comment = '(8/7 SP1/Vista SP2)'               }
        '379893' = @{ Version = [System.Version]'4.5.2'                                                   }
        '380042' = @{ Version = [System.Version]'4.5'     ; Comment = 'and later with KB3168275 rollup'   }
        '393295' = @{ Version = [System.Version]'4.6'     ; Comment = '(Windows 10)'                      }
        '393297' = @{ Version = [System.Version]'4.6'     ; Comment = '(NON Windows 10)'                  }
        '394254' = @{ Version = [System.Version]'4.6.1'   ; Comment = '(Windows 10)'                      }
        '394271' = @{ Version = [System.Version]'4.6.1'   ; Comment = '(NON Windows 10)'                  }
        '394802' = @{ Version = [System.Version]'4.6.2'   ; Comment = '(Windows 10 Anniversary Update)'   }
        '394806' = @{ Version = [System.Version]'4.6.2'   ; Comment = '(NON Windows 10)'                  }
        '460798' = @{ Version = [System.Version]'4.7'     ; Comment = '(Windows 10 Creators Update)'      }
        '460805' = @{ Version = [System.Version]'4.7'     ; Comment = '(NON Windows 10)'                  }
        '461308' = @{ Version = [System.Version]'4.7.1'   ; Comment = '(Windows 10 Fall Creators Update)' }
        '461310' = @{ Version = [System.Version]'4.7.1'   ; Comment = '(NON Windows 10)'                  }
        '461808' = @{ Version = [System.Version]'4.7.0356';                                               }
        '461814' = @{ Version = [System.Version]'4.7.2'   ;                                               }
        '528040' = @{ Version = [System.Version]'4.8';                                                    }
        '528049' = @{ Version = [System.Version]'4.8';                                                    }    
        '528372' = @{ Version = [System.Version]'4.8';                                                    }          
    }

    foreach($computer in $ComputerName)
    {
        if($regKey = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $computer))
        {
            if ($netRegKey = $regKey.OpenSubKey("$dotNetRegistry"))
            {
                foreach ($versionKeyName in $netRegKey.GetSubKeyNames())
                {
                    if ($versionKeyName -match '^v[123]') {
                        $versionKey = $netRegKey.OpenSubKey($versionKeyName)
                        $version = [System.Version]($versionKey.GetValue('Version', ''))
                        New-Object -TypeName PSObject -Property ([ordered]@{
                                ComputerName = $computer
                                Build = $version.Build
                                Version = $version
                                Comment = ''
                        })
                    }
                }
            }

            if ($net4RegKey = $regKey.OpenSubKey("$dotNet4Registry"))
            {
                if(-not ($net4Release = $net4RegKey.GetValue('Release')))
                {
                    $net4Release = 30319
                }
                New-Object -TypeName PSObject -Property ([ordered]@{
                        ComputerName = $Computer
                        Build = $net4Release
                        Version = $dotNet4Builds["$net4Release"].Version
                        Comment = $dotNet4Builds["$net4Release"].Comment
                })
            }
        }
    }
}

Get-DotNetFrameworkVersion