If I have had a good time playing around in Powershell, and got really big mess in installed modules and installed DSC rescourceses how can I clean everything up and get back to start? Start mening like my computer were newly installed ?
There isn’t a way to ‘reset’ it per se, that I’m aware of. My first thought was to use Compare-Object against a “clean computer” for a baseline, but that’s kind of dangerous because if you have features installed on one system and not the other (like RSAT\ActiveDirectory module) it could break things. The first question is where are you installing the modules? If you go to a prompt and type $env:PSModulePath, it will provide the directories that Powershell references when searching for Modules:
PS C:\Users\Rob> $env:PSModulePath C:\Users\Rob\Documents\WindowsPowerShell\Modules;C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\;C:\Users\Rob\Dropbox\Scrip ts\Powershell\SAPIEN\Projects\
Typical, “user installed” modules would most likely exist in the first path (C:\Users\Rob\Documents\WindowsPowerShell\Modules). This doesn’t exist by default, so you could remove anything in there to reset modules. If you are installing “system” modules, those typically go into C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules</em>. You can do into that directory and specifically delete modules you don’t need, but that’s where your “default” modules for the OS, Windows features, etc. are, so be careful. I don’t see many modules installed in C:\Program Files\WindowsPowerShell\Modules, but you can check there as well. Of course, you have to do it with Powershell 
:
$modules = foreach ($module in Get-ChildItem ($env:PSModulePath -split ";")) {
$module | Select Name, FullName, LastWriteTime, CreationTime
}
$modules | Where{$_.Name -eq "PSDesiredStateConfiguration"} | Remove-Item -Recurse -Force
The $modules should look like this:
PS C:\Users\Rob> $modules Name FullName LastWriteTime CreationTime ---- -------- ------------- ------------ Microsoft.PowerShell.Operation.Validation C:\Program Files\WindowsPowerShell\Modules\Microsoft.PowerShell.Operation.Validation 7/16/2016 7:47:47 AM 7/16/2016 7:47:... PackageManagement C:\Program Files\WindowsPowerShell\Modules\PackageManagement 7/16/2016 7:47:47 AM 7/16/2016 7:47:... Pester C:\Program Files\WindowsPowerShell\Modules\Pester 8/16/2016 2:56:59 PM 7/16/2016 7:47:... PowerShellGet C:\Program Files\WindowsPowerShell\Modules\PowerShellGet 7/16/2016 7:47:48 AM 7/16/2016 7:47:... PSReadline C:\Program Files\WindowsPowerShell\Modules\PSReadline 8/16/2016 2:56:59 PM 7/16/2016 7:47:... AppBackgroundTask C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\AppBackgroundTask 10/24/2016 12:51:11 PM 7/16/2016 7:47:... Appx C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\Appx 10/24/2016 12:51:11 PM 7/16/2016 7:47:... BitLocker C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\BitLocker 10/24/2016 12:51:12 PM 7/16/2016 7:47:... BitsTransfer C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\BitsTransfer 10/24/2016 12:51:12 PM 7/16/2016 7:47:... CimCmdlets C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\CimCmdlets 10/24/2016 12:51:13 PM 7/16/2016 7:47:...
You could just datetime searches to see if you can find most of the newer stuff that you want to remove and just pipe it to Remove-Item. We’ll see if anyone else has any insight.