[windows] IE Enable/Disable Proxy Settings via Registry

I need to enable/disable IE proxy settings while IE is running. I have a PowerShell script line to enable the proxy:

Set-ItemProperty -Path "Registry::HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" ProxyEnable -value 1

or this to disable:

Set-ItemProperty -Path "Registry::HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" ProxyEnable -value 0

Above scripts work, registry key gets updated. However, IE doesn't pick up the value until I close all the open IE windows and open a new one. I need already opened/running IE windows to pick up the new setting.

Would there be any way to achieve what I want?

I know this is an old question, however here is a simple one-liner to switch it on or off depending on its current state:

set-itemproperty 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings'  -name ProxyEnable -value (-not ([bool](get-itemproperty 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings'  -name ProxyEnable).proxyenable))

The problem is that IE won't reset the proxy settings until it either

1. closes, or
2. has its configuration refreshed.

Below is the code that I've used to get this working:

function Refresh-System
{
  $signature = @'
[DllImport("wininet.dll", SetLastError = true, CharSet=CharSet.Auto)]
public static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int dwBufferLength);
'@

$INTERNET_OPTION_SETTINGS_CHANGED   = 39
$INTERNET_OPTION_REFRESH            = 37
$type = Add-Type -MemberDefinition $signature -Name wininet -Namespace pinvoke -PassThru
$a = $type::InternetSetOption(0, $INTERNET_OPTION_SETTINGS_CHANGED, 0, 0)
$b = $type::InternetSetOption(0, $INTERNET_OPTION_REFRESH, 0, 0)
return $a -and $b
}

modifying the proxy value under

[HKEY_USERS\<your SID>\Software\Microsoft\Windows\CurrentVersion\Internet Settings]

doesnt need to restart ie