I have the same problem, after downloading a fresh installer.

 - Configuring IIS logging...
Add-PSSnapin : No snap-ins have been registered for Windows PowerShell version
2.
At C:\AutoSPInstallerv3\SP\AutoSPInstaller\AutoSPInstallerFunctions.ps1:5364 ch
ar:29
+                 Add-PSSnapin <<<<  WebAdministration
    + CategoryInfo          : InvalidArgument: (WebAdministration:String) [Add
   -PSSnapin], PSArgumentException
    + FullyQualifiedErrorId : AddPSSnapInRead,Microsoft.PowerShell.Commands.Ad
   dPSSnapinCommand

--------------------------------------------------------------
 - Script halted!


Exception             : System.Management.Automation.CommandNotFoundException:
                        The term 'Get-WebConfigurationProperty' is not recogniz
                        ed as the name of a cmdlet, function, script file, or o
                        perable program. Check the spelling of the name, or if
                        a path was included, verify that the path is correct an
                        d try again.
                           at System.Management.Automation.CommandDiscovery.Loo
                        kupCommandInfo(String commandName, CommandOrigin comman
                        dOrigin)
                           at System.Management.Automation.CommandDiscovery.Loo
                        kupCommandProcessor(String commandName, CommandOrigin c
                        ommandOrigin, Nullable`1 useLocalScope)
                           at System.Management.Automation.ExecutionContext.Cre
                        ateCommand(String command)
                           at System.Management.Automation.CommandNode.CreateCo
                        mmandProcessor(Int32& index, ExecutionContext context)
                           at System.Management.Automation.CommandNode.AddToPip
                        eline(PipelineProcessor pipeline, ExecutionContext cont
                        ext)
                           at System.Management.Automation.PipelineNode.Execute
                        (Array input, Pipe outputPipe, ArrayList& resultList, E
                        xecutionContext context)
                           at System.Management.Automation.ParseTreeNode.Execut
                        e(Array input, Pipe outputPipe, ExecutionContext contex
                        t)
                           at System.Management.Automation.AssignmentStatementN
                        ode.Execute(Array input, Pipe outputPipe, ExecutionCont
                        ext context)
                           at System.Management.Automation.StatementListNode.Ex
                        ecuteStatement(ParseTreeNode statement, Array input, Pi
                        pe outputPipe, ArrayList& resultList, ExecutionContext
                        context)
TargetObject          : Get-WebConfigurationProperty
CategoryInfo          : ObjectNotFound: (Get-WebConfigurationProperty:String) [
                        ], CommandNotFoundException
FullyQualifiedErrorId : CommandNotFoundException
ErrorDetails          :
InvocationInfo        : System.Management.Automation.InvocationInfo
PipelineIterationInfo : {}
PSMessageDetails      :

Hi mht

What version of windows server are you running, I would assume since you try to use PSSnapin your using windows server 2008 not (2008R2 or 2012)

This looks like that your snapin was not installed correctly, Try and re install the IIS7 snapin again. (You could do this manual if you don't have it in the pre-0require installer folder "$env:SPbits\PrerequisiteInstallerFiles\iis7psprov_x64.msi`")

Here is the link to the installation
http://www.iis.net/downloads/microsoft/powershell


Torben.