Deleting all locally stored user profiles on log off - powershell

Question

I want to delete all locally stored user profiles on logoff using a Powershell script. I've the following script:
Set-ExecutionPolicyRemoteSigned[gc]::collect()
cmd /c start reg unload "HKCU"Remove-PSDrive HKCU import-module C:\Windows\System32\WindowsPowerShell\v1.0\Modules\ManageUserProfiles\ManageUserProfiles.PSM1
get-userprofile |where{ $_.SID -ne ("S-1-5-21-3071724114-2656578308-4228372245-500")} | remove-userprofile
I'm a complete newbie to powershell. So could someone tell me whether this script meets my needs and how does it run? And could you also explain what $_.SID -ne ("S-1-5-21-3071724114-2656578308-4228372245-500") means too. Thanks in advance.

Answer 1

I am not familiar with the module that you are running, and it looks like that should be 6 lines not 3 (insert break before [gc], before Remove-PSDrive, and before Import-Module).
Next, add a space between Set-ExecutionPolicy and RemoteSigned.
Now, the script appears to collect user profiles, pipes them through a Where statement that excludes the Administrator account from the list of profiles, and then removes all remaining profiles. Let's step through it...
Set-ExecutionPolicy RemoteSigned
This sets your execution policy. I'm going to assume this is to avoid issues with an unsigned module that you load in a couple steps.
[gc]::collect()
This forces the garbage collection to clean up memory and remove unused resources. This line can probably be skipped.
cmd /c start reg unload "HKCU"
This uses the reg.exe command line application to unload the HKEY_CURRENT_USER hive from within the current registry set. This would need to be done before deleting a profile since you can't delete files that are in use.
Remove-PSDrive HKCU
This does pretty much the same thing, but for PowerShell's registry provider. I'm guessing this is so that you don't get errors, or so that it doesn't try to reload the HKCU hive.
C:\Windows\System32\WindowsPowerShell\v1.0\Modules\ManageUserProfiles\ManageUserProfiles.PSM1
This loads the 'Manage User Profiles' module. I am not familiar with the module, but you would need to make sure that you have that module installed on the computer that this is running on, so if you are running this on all of your computers you need to install that module on all of your computers.
get-userprofile |where{ $_.SID -ne ("S-1-5-21-3071724114-2656578308-4228372245-500")} | remove-userprofile
This is a command from the module you just loaded. It will, I assume, get user profiles as some sort of custom object, and then it pipes to a Where statement that excludes the Administrator account by stating that it only allows profile objects that do not (-ne is the 'not equal' operator) have a SID property equal to "S-1-5-21-3071724114-2656578308-4228372245-500". So all user profiles except the admin account's profile are then piped to the Remove-UserProfile command, which we can probably assume deletes each profile that is piped to it.
Hopefully that explains what your script is doing.