Strange Error with Powershell when downloading files - powershell

Question

I got a very strange error when trying to install dnvm on powershell. Actually I get this error with any attempt to download anything, e.g. "wget" produces a similar error.
I thought first that I don't have the rights to execute but running this in an Administrator shell + I changed the Security Policy.
Then I figured that the PS doesn't have access to the internet, so I adjusted the Firewall and even added PS to the allowed programs. No luck!
Now the weird thing is that I can download files just fine via IE.
This is the error that I get
Exception calling "DownloadString" with "1" argument(s): "An exception occurred during a WebClient request."
At line:1 char:17
+ &{$Branch='dev';iex ((new-object net.webclient).DownloadString('https://raw.gith ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : WebException
Anyone as an idea?
Also this is a machine running on AWS.

Answer 1

This is a shot in the dark, but first thing that comes to mind is proxy settings.
System.Net.WebClient does not automatically pick up IE's proxy configuration, but you should be able to force it to do so with:
$WebClient = New-Object System.Net.WebClient
$WebProxy = [System.Net.WebProxy]::GetDefaultProxy()
$WebClient.Proxy = $WebProxy
$WebClient.DownloadString($url)
or with your very compact syntax:
&{$Branch='dev';($w=New-Object Net.WebClient).Proxy=[Net.WebProxy]::GetDefaultProxy();iex $w.DownloadString($url)}