#requires -version 2.0

# -----------------------------------------------------------------------------
# Script: get-registry.ps1
# Version: 1.0
# Author: Jeffery Hicks
#    http://jdhitsolutions.com/blog
#    http://twitter.com/JeffHicks
#    http://www.ScriptingGeek.com
# Date: 5/4/2011
# Keywords: Registry, WMI
# Comments: 
#
# "Those who forget to script are doomed to repeat their work."
#
#  ****************************************************************
#  * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
#  * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK.  IF   *
#  * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
#  * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING.             *
#  ****************************************************************
# -----------------------------------------------------------------------------

Function Get-Registry {

<#
.SYNOPSIS
Get registry size and utilization
.DESCRIPTION
This command uses WMI to retrieve size and status information for the Windows registry. Sizes are provided in MB. This version has no provision for alternate credentials.
.PARAMETER Computername
The name of a computer to query. The default is the local host.
.EXAMPLE
PS C:\> Get-Registry

Computername : SERENITY
Status       : OK
CurrentSize  : 185
MaximumSize  : 2048
FreeSize     : 1863
PercentFree  : 90.966796875
Created      : 1/28/2011 4:12:23 PM
Age          : 95.17:40:14.1730245

Return registry usage information for the local host.
.EXAMPLE
PS C:\> Get-Content Computers.txt | Get-Registry | Export-CSV c:\work\RegistryReport.csv
Retrieve registry usage information for all the computers in the text file, computers.txt. The results
are exported to a CSV file.
.NOTES
NAME        :  Get-Registry
VERSION     :  1.0   
LAST UPDATED:  5/4/2011
AUTHOR      :  Jeffery Hicks
.LINK
http://jhdhitsolutions.com/blog/2011/05/get-registry-size-and-age
.LINK
Get-WMIObject 
.INPUTS
String
.OUTPUTS
A custom object
#>

[cmdletbinding()]

Param (
[Parameter(Position=0,ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$True)]
[ValidateNotNullorEmpty()]
[String[]]$Computername=$env:Computername
)

Begin {
    Write-Verbose "Starting $($myinvocation.mycommand)"
} #Begin

Process {
    Foreach ($computer in $computername) {
        Write-Verbose "Processing $computer"
        Try {
         #retrieve registry information via WMI
         $data=Get-WmiObject -Class Win32_Registry -ComputerName $computer -ErrorAction Stop
         #Format the results and write an object to the pipeline
         $data | Select-Object -Property @{Name="Computername";Expression={$_.__SERVER}},
         Status,CurrentSize,MaximumSize,@{Name="FreeSize";Expression={$_.MaximumSize - $_.CurrentSize}},
         @{Name="PercentFree";Expression={ (1 - ($_.CurrentSize/$_.MaximumSize))*100 }},
         @{Name="Created";Expression={$_.ConvertToDateTime($_.InstallDate)}},
         @{Name="Age";Expression={(Get-Date) - ( $_.ConvertToDateTime($_.InstallDate)) }}
         
        } #try
        
        Catch {
            Write-Warning "Failed to retrieve registry information from $($Computer.ToUpper())"
            Write-Warning $_.Exception.Message
        }#Catch
    
    }#foreach $computer
} #Process

End {
    Write-Verbose "Ending $($myinvocation.mycommand)"
} #End

} #end function